Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Variant transthyretin amyloidosis (ATTRv) is a rare genetic disease that affects patients’ quality of life by affecting various organs and tissues. Despite a wealth of research on medical and psychosocial interventions, the impact of occupational therapy on patients with ATTRv is not well understood. This research focuses on the assessment of activities of daily living and occupations as a fundamental tool in the management of patients after diagnosis.
Objective: The aim of this study was to develop an occupational therapy programme for the improvement of daily functioning and quality of life in patients with ATTRv.
Methods: After an initial semi-structured interview, fourteen patients with ATTRv were enrolled in the study. The occupational therapist worked with the patient to develop short- and medium-term occupational goals, based on the Model of Human Occupation. During the six-month intervention period, weekly or ten-day sessions were held to monitor and adjust the guidelines. Outcomes were measured using scores for activities of daily living and psychological well-being.
Results: The results showed that twelve patients stayed the same in their activities of daily living, two got worse and eight improved their psychological scores and the occupational situation. The study highlights the importance of early intervention and further research into the effectiveness of occupational therapy interventions for patients with ATTRv. It also notes that patients who received occupational therapy intervention reported that 6 months was not enough and emphasizes the fundamental role of the therapist in providing motivation, facilitating meaningful activities, improving daily living and routines.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: A recent real-world survey study evaluated the multidimensional burden of transthyretin amyloid cardiomyopathy (ATTR-CM) in 208 pairs of patients treated with symptomatic but not disease-modifying therapy and their unpaid primary caregivers, recruited from amyloidosis centers of excellence in 7 countries.
Methods: This post hoc analysis used univariate and multivariate analyses to evaluate selected study items as predictors of caregiver burden, as measured by their Zarit Burden Interview (ZBI) score (range 0–88; higher scores indicate a higher burden).
Results: Caregivers in the original study were generally female (85%) and the spouse (59%) of the patient, with a median ZBI score of 13. Patients were generally male (86%) and elderly (median age 81 years), with symptomatic heart failure. Their median Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS) score was 68, and median Hospital Anxiety and Depression Scale (HADS) sub-scores were both <8. In univariate associations, the patient’s New York Heart Association class, KCCQ-OS, and HADS sub-scores were significantly (p < .05) associated with caregiver’s continuous or categorical ZBI scores. In the full multivariate models, the patient’s KCCQ-OS score was the only significant (p < .05) predictor of caregiver burden. The final models were optimized using forward selection and CV Press criteria with 8-fold cross-validation. Both included only KCCQ-OS as a predictor of continuous (regression coefficient: −0.26 [95% CI: −0.33, −0.20]) and categorical (odds ratio for no burden vs mild to moderate burden: 0.96 [95% CI: 0.94, 0.97]) ZBI score.
Conclusion: A higher caregiver burden was best predicted by poorer health status in the patient.
Abstract
Topic: Prognosis AL.
Background: Survival in light chain (AL) amyloidosis is determined by cardiac involvement, and prognosis has been based on the revised Mayo(rMayo) staging. Other clinical prognostic values have been suggested, such as left ventricular (LV) global longitudinal strain and left atrial (LA) strain. We aim to verify whether LA stiffness index (ratio of LA reservoir strain (LARS) to E/e’) (LASI), a factor that reflects both LA and LV, can predict the outcome of AL amyloidosis.
Method: 211 AL amyloidosis patients from a prospective registry were analyzed (January 2015–June 2022). All had confirmed diagnosis either by cardiac biopsy or an involved organ with echocardiography. Patients were categorized according to rMayo stage at diagnosis, including difference between free light chains, N-terminal pro B-type natriuretic peptides (NT-proBNP) and troponin. Clinical outcomes included worsening heart failure (HF) and all-cause mortality.
Result: The median overall survival was 47.7 months (IQR: 13.3–114.0), and 106 (50.0%) patients died. LASI showed significant correlation with NT-proBNP (r = 0.202, p = .003), right ventricular systolic pressure (r = 0.236, p = .002), LV ejection fraction (r = −0.353, p < .001) and incremental values over rMayo staging for predicting all-cause mortality. LASI ≥1.2 was the best cut-off point (AUC =0.631, 95% CI: 0.593–0.742, p = .001). LASI ≥1.2 with rMayo stage III compared to LASI <1.2 with rMayo stage IV presented with significant survival differences (median overall survival:17.0 vs 35.0 months, p = .012). Patients with rMayo stage IV and LASI ≥1.2 had the worst median overall survival of 5 months.
Conclusion: LASI is an independent predictor for all-cause mortality and has incremental predictive value over the current staging system. Patients with increased LASI also had worsening HF and increased risk of stroke.
Abstract
Topic: Treatments of ATTR
Background: In the pivotal phase 3 trial, tafamidis significantly reduced mortality and the rate of cardiovascular hospitalizations compared with placebo in patients with transthyretin amyloid cardiomyopathy (ATTR-CM), supporting its approval in many countries. This post-approval commitment study evaluated the safety and efficacy of tafamidis in Chinese patients with ATTR-CM.
Methods: This was a multicenter, single-arm study in adult Chinese patients with symptomatic ATTR-CM in China. All patients received once-daily open-label tafamidis free acid 61 mg for 12 months. Safety reporting was ongoing with efficacy assessments at Months 6 and 12, including the 6-min walk test, N-terminal pro-B-type natriuretic peptide concentration, Kansas City Cardiomyopathy Questionnaire, 5-level EQ-5D instrument, and 12-item short form survey.
Results: In all, 53 patients with a mean age of 60 (SD: 12) years were enrolled between July 2021 and September 2022. Most were male (89%), with variant ATTR-CM (94%; A97S [p.A117S] in 21%) and New York Heart Association functional class II at baseline (81%; 6% class I; 13% class III). Overall, 85% of patients reported treatment-emergent adverse events (TEAEs), which were consistent with the known tafamidis safety profile and generally mild (in 44% of all patients with TEAEs) or moderate (18%) in severity. There were no serious or severe treatment related TEAEs. At Month 12, overall change from baseline in efficacy measures suggested disease stabilization, including no deterioration in health status (Table).
Conclusions: The safety of tafamidis in Chinese patients with ATTR-CM was consistent with that previously observed, and treatment was associated with a stable disease profile. NCT04814186.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis (ATTR) is now widely recognized as a rare spectrum disease manifesting as ATTR polyneuropathy, ATTR cardiomyopathy (ATTR-CM), or a mixed phenotype. High-dose tafamidis (61 mg) is a first-in-class highly specific and selective stabilizer of both wild-type ATTR (ATTRwt) and variant ATTR (ATTRv) approved worldwide to reduce cardiovascular mortality and cardiovascular-related hospitalization in ATTR-CM. A recent exploratory real-world study in the United States demonstrated high-dose tafamidis was beneficial for delaying neurologic disease progression in patients with mixed-phenotype ATTRv-CM exposed to tafamidis for >6 months. The most recent Transthyretin Amyloidosis Outcomes Survey analysis reported that almost half of mixed phenotype ATTR amyloidosis patients in North America were ATTRwt genotype. The current study will assess the benefit of high-dose tafamidis treatment on neurologic disease progression in mixed-phenotype ATTRv-CM or ATTRwt-CM patients treated with tafamidis for >12 months in a real-world setting.
Methods: This retrospective, non-interventional cohort study will include approximately 50 patients from the United States with mixed-phenotype ATTRv-CM or ATTRwt-CM treated with tafamidis 61 mg for at least 12 months. Anonymized patient data will be collected from electronic medical records pre- and post-tafamidis treatment. Assessments will include the neuropathy impairment score (NIS) subscales, polyneuropathy disability (PND) score, Medical Research Council (MRC) Scale for Muscle Strength, and modified body mass index (mBMI). Data analysis will be descriptive.
Results: Available results will be provided at the time of the meeting.
Conclusions: This study will elucidate the benefit of long-term high-dose tafamidis treatment on neurologic progression in mixed phenotype ATTRv-CM and ATTRwt-CM.
Abstract
Topic: Diagnosis ATTRv
Background: The Transthyretin Amyloidosis Outcomes Survey (THAOS; NCT00628745) was the largest longitudinal, observational, phase 4 study of patients with transthyretin amyloidosis (ATTR amyloidosis), including both hereditary and wild-type (ATTRwt amyloidosis) disease, and asymptomatic carriers of pathogenic transthyretin (TTR) variants. This analysis provides a final, consolidated overview of 16 years of patient data from THAOS.
Methods: Baseline demographic and clinical characteristics of symptomatic patients and asymptomatic gene carriers from THAOS are described. Results are based on the completed THAOS dataset (data cutoff: 24 July 2023).
Results: There were 6718 patients (4699 symptomatic, 1738 asymptomatic carriers, 281 unclassified) enrolled in THAOS. Symptomatic patients were primarily male (70.8%) and median age at symptom onset was 59.5 years. The most prevalent genotype was V30M in Europe (53.5%), South America (74.0%), and Japan (75.0%), and ATTRwt amyloidosis in North America (60.1%). The most prevalent phenotype was predominantly neurologic in Europe (47.8%), South America (60.8%), and Japan (55.9%), and predominantly cardiac in North America (64.4%). In Europe, South America, Japan, and North America, respectively, 26.5%, 26.7%, 30.9%, and 18.4% of patients had a mixed phenotype. Asymptomatic carriers were 58.0% female and median age at enrollment was 39.4 years; V30M was the most prevalent TTR variant (74.0%).
Conclusions: This descriptive analysis of over 6000 patients from THAOS is the largest overview of ATTR amyloidosis to date. Results revealed regional differences in the distribution of genotypes and phenotypes. The increasing proportion of patients with a mixed phenotype worldwide reinforces the need for multidisciplinary management of ATTR amyloidosis.
Abstract
Topic: Treatments of ATTR
Background: Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) present with diverse left ventricular ejection fraction (LVEF). This post-hoc analysis assessed tafamidis efficacy by baseline LVEF in patients who enrolled in the phase 3 Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT) and its long-term extension (LTE) study.
Methods: Patients were randomized to 30 months of tafamidis or placebo treatment in ATTR-ACT. On completion, patients could join an LTE study to receive tafamidis. All-cause mortality (death, heart transplant, or cardiac mechanical assist device implantation) from baseline to the end of follow-up was assessed in patients continuously treated with tafamidis (80 mg meglumine or 61 mg free acid) or delayed tafamidis treatment (placebo in ATTR-ACT; tafamidis in the LTE study) according to baseline LVEF (</≥50%). Supportive outcomes were evaluated over a shorter follow-up.
Results: Patients with baseline LVEF <50% (n = 177: 88 tafamidis- and 89 placebo-treated) had signs of more severe heart failure, a higher proportion were Black and had variant ATTR-CM than those with LVEF ≥50% (n = 171: 85 tafamidis- and 86 placebo-treated). At the end of follow-up (median 60–64 months), all-cause mortality was numerically higher in patients with baseline LVEF <50% but, consistent with supportive findings, continuous tafamidis treatment was associated with a 47% reduction in mortality risk in patients with LVEF <50% (hazard ratio: 0.53 [95% CI: 0.367–0.758]; p < .001) and in those with LVEF ≥50% (0.53 [0.344–0.818]; p < .01) compared with delayed tafamidis.
Conclusions: Early initiation of tafamidis is associated with reduced mortality in patients with ATTR-CM, irrespective of initial LVEF value. NCT01994889; NCT02791230.
Abstract
Topic: Basic Science AL
Systemic immunoglobulin light chain (AL) amyloidosis is a protein misfolding disease caused by the conversion of immunoglobulin light chains (LC) from their soluble dimeric functional states into highly organized amyloid fibrils. Fibrillar deposition of LCs severely affects organ function and results in poor prognosis for patients, especially when heart involvement is severe. In addition to fibrillar deposition, a further important pathogenic factor is represented by the direct toxicity of soluble pre-amyloid LCs. With the goal of identifying alternative therapeutic strategies to tackle AL amyloidosis, we describe the identification and molecular determination of six llama-derived nanobodies (Nbs) directed to H3, an amyloidogenic LC from an AL patient with severe cardiac involvement. We demonstrated that the Nbs complexed to H3 abolish LC toxicity in the C. elegans in vivo model. We showed that Nbs stabilize H3 native fold and that they bind to their target with affinities in the nanomolar range. Finally, crystal structures of H3-Nb complexes show that Nbs form large interaction surfaces with H3 monomeric variable (VL) domains, stabilizing a partially monomeric LC conformation. Overall, our results show that by the formation of a stabilizing complex between soluble LCs and a specific binder, it is possible to abrogate LC cardiotoxicity; moreover, we picture an unreported partially monomeric LC dimer representing a conformation likely specific for amyloidogenic and toxic LCs. Such conformation may be the one directly responsible for the observed soluble cardiotoxicity or at least an obligate step towards the formation of the toxic species.
Abstract
Topic: Diagnosis ATTRwt
Background: Identification of elderly patients with concomitant positivity of bisphosphonate scintigraphy and monoclonal protein testing is increasing. In this case, accurate amyloid histologic subtyping is crucial.
Methods: Among 133 patients with a diagnosis of cardiac amyloidosis, 21 (16%) presented with an abnormality of both bisphosphonate scintigraphy and serum-immunofixation and underwent abdominal fat biopsy/needle aspiration. In case of negative results, an endomyocardial biopsy (EMB) was planned. Amyloid was identified at histology by Congo Red staining. Amyloid typing was obtained by immunohistochemistry using a recently developed amyloid antibody panel AmYkit (Amimed). The results were compared with those obtained with standard immunohistochemistry.
Results: Sixteen of the 21 patients were older than 75 years (76%, 81 ± 10 years) with a grade 3 (62%) or 2 (33%) scintigraphy. One patient showed a grade 1 positive scintigraphy. Serum-immunofixation revealed a previously unknown monoclonal protein peak in 78%, while 22% had a history of MGUS. No patient had hematologic disorders. TTR pathogenic mutation was detected in one patient. Abdominal fat was negative for amyloid while Congo Red staining was positive in all examined EMBs. Immunohistochemistry with standard antibodies was not able to discriminate between AL and ATTR. Our preliminary results with AmYkit panel of antibodies demonstrate absence of signal overlapping in over 90% of cases, allowing accurate histologic discrimination between AL and TTR.
Conclusion: In elderly patients with positivity of both bisphosphonate scintigraphy and monoclonal protein testing, TTR is the most frequent type of cardiac amyloid. Accurate amyloid subtyping is granted by a more sensitive panel of antibodies.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
Calcific aortic valve disease is a prevalent life-threatening heart disease in search of pharmacological treatments. To find such treatments, we need to better understand modulators of valvular calcification. Amyloid and collagen fibrils are often adjacent to calcified areas in explanted aortic valve tissues. Moreover, explanted valvular amyloid promotes calcification in vitro. Stereochemical complementarity between acidic arrays on the amyloid surface and the 4.7 Å Ca-Ca spacing in amorphous hydroxyapatite suggests a template-based mechanism for amyloid-guided calcification, yet the role of collagen is unclear. To explore this role, we used collagens I–IV with various amyloidogenic proteins including apolipoprotein A-I (apoA-I); upon oxidation, apoA-I forms amyloid that deposits in atherosclerotic plagues. Human plasma-purified apoA-I was oxidized (oxA-I) to convert Met residues to Met(O), followed by 72 h incubation under amyloid-promoting conditions. Amyloid formation was monitored by spectroscopy (CD, FT IR, fluorescence) and electron microscopy. ELISA showed that formation of apoA-I amyloid oligomers and fibrils enhances apoA-I–collagen binding. To test whether this binding influences biomineralization, apoA-I fibrils mixed with collagen-I (up to 1:1 protein:collagen wt:wt) were incubated in modified simulated body fluid at 37 °C for 50h. Abundant hydroxyapatite crystals were observed surrounding apoA-I + collagen-I fibrils; few crystals formed with collagen-I fibrils alone, and no crystals formed with apoA-I fibrils alone. Our results suggest that apoA-I amyloid binds collagen-I, thereby forming acidic arrays on the matrix that promote biomineralization. Other amyloid proteins (lysozyme, insulin, and serum amyloid A) showed similar effects. Emerging atomic structures of amyloid-collagen fibrils may help elucidate their role in degenerative calcification.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
Apolipoproteins are ‘amyloid signature proteins’, yet apolipoprotein-amyloid interactions are enigmatic. To understand how apoE interacts with Alzheimer’s amyloid-beta peptide in fibrillary deposits, the NMR structure of full-length human apoE was docked to four structures of patient-derived Abeta(1–40) and Abeta(1–42) fibrils determined previously using cryo-electron microscopy or solid-state NMR. Similar docking was done using the structures of human apoC-III and of an apolipoprotein consensus peptide. In all complexes, conformational changes were required to expose large hydrophobic faces of apolipoprotein amphipathic alpha-helices for sub-stoichiometric binding to hydrophobic surfaces on fibril sides or ends. Basic residues flanking the hydrophobic helical faces in apolipoproteins interacted favorably with acidic residue ladders in some amyloid polymorphs. Molecular dynamics simulations of selected apoE-fibril complexes confirmed their stability. Amyloid binding via cryptic sites, which became exposed upon opening of flexibly linked apolipoprotein alpha-helices, resembled apolipoprotein-lipid binding. This mechanism extends to other apolipoprotein-amyloid interactions. Apolipoprotein binding alongside fibrils could interfere with fibril fragmentation and secondary nucleation, while binding at the fibril ends could halt amyloid elongation and dissolution in a polymorph-specific manner. The proposed mechanism is supported by extensive prior experimental evidence and helps reconcile disparate reports on apoE’s role in Abeta aggregation. Furthermore, apoE domain opening and direct interaction of Arg/Cys158 with amyloid potentially contributes to isoform-specific effects in Alzheimer’s disease. In summary, current modeling supported by prior experimental studies suggests similar mechanisms for apolipoprotein-amyloid and apolipoprotein-lipid interactions; explains why apolipoproteins co-deposit with amyloids; and helps reconcile conflicting reports on the chaperone-like apoE action in Abeta aggregation.
Abstract
Topic: Diagnosis ATTRwt
Background: The objective of this prospective cohort study is to build a risk score based on risk factors independently associated with a positive tenosynovial biopsy for amyloid deposition at carpal tunnel release for patients with presumed idiopathic carpal tunnel syndrome.
Methods: We conducted a prospective cohort study of adult patients with electrodiagnostic study-confirmed or ultrasound-confirmed carpal tunnel syndrome undergoing carpal tunnel release at a tertiary medical center. 320 patients who underwent carpal tunnel release were enrolled and underwent tenosynovial biopsy at the time of surgery. The primary outcome measure will be a positive biopsy for amyloid. We assigned points to each variable proportional to the estimates from a logistic regression model to generate a risk score.
Results: The mean age of the cohort was 63 years, and 65% of patients were female. Forty-nine of 320 patients (15.3%) who underwent carpal tunnel release had positive tenosynovial biopsies for amyloidosis. The logistic regression model was used to generate an amyloidosis risk score based on age, sex, and history of trigger digit (Table 1). The amyloidosis risk score is adequately discriminating, with a score of 0 representing 2.5% risk and a score of 6 representing 75% risk (Figure 1).
Discussion: A positive tenosynovial biopsy is seen in 15% of all adults undergoing carpal tunnel release for idiopathic carpal tunnel syndrome. The likelihood of a positive biopsy for amyloidosis is independently associated with older age. We recommend tenosynovial biopsy at an amyloidosis risk score cutoff of ≥3, which yields 88% sensitivity in detecting amyloidosis.
Abstract
Topic: Diagnosis ATTRwt
The diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) can be difficult to establish, particularly at an early stage, due to a multitude of reasons. It may initially present with extracardiac symptoms and requires a high index of clinical suspicion together with a certain level of expertise and a multimodality imaging approach to confirm the diagnosis.
The prevalence of ATTR-CA in the Middle East, and particularly in the largest country that is Saudi Arabia is significantly underrepresented in the literature. Recent studies conducted in the Middle East and the Gulf region demonstrate significant shortcomings regarding the diagnostic modalities and therapeutic approaches for cardiac amyloidosis, mainly due to a lack of awareness among health care professionals.
Limited data are available regarding the prevalence, incidence, and clinical features of ATTR-CA in the Middle East and Gulf region (mainly Saudi Arabia). Based on international epidemiological studies, the majority of cases of cardiac amyloidosis in this region remain undiagnosed. Studies published over the past decade, mainly in western countries, indicate that ATTR-CA is more common than previously believed and that it is significantly underdiagnosed.
Implementing these measures would improve the diagnosis and management of cardiac amyloidosis in the region, thereby allowing for disease detection at an earlier stage and the utilization of targeted disease-modifying therapies.
The application of AHA and ESC guidelines regarding the diagnosis and management of cardiac amyloidosis in our region is likely to lead to significant advances in understanding the epidemiology and clinical features of the disease.
Abstract
Topic: Prognosis AL
Background: The prognostic significance of cytogenetic abnormalities by FISH in the context of daratumumab-based frontline therapy is not well-defined.
Methods: We conducted a multicenter retrospective cohort study investigating Dara-VCD/Dara-VD efficacy in cytogenetic subgroups: t(11;14), +1q, hyperdiploidy, deletion(13q), and high-risk abnormalities (t(4;14), t(14;16), t(14;20), and/or del(17p)). Key endpoints included heme-CR rate, ≥heme-VGPR rate, and hematologic event-free survival (Heme-EFS: time from treatment initiation to subsequent therapy/death)
Results: A total of 267 patients who had started Dara-VCD/Dara-VD by 12/31/2022 were included, with 244 having baseline FISH. The incidence of abnormalities was as following: t(11;14)-52%; deletion(13q)-30%; hyperdiploidy-29%; +1q-22%; and HR-9%. The heme-CR rate by cytogenetic subgroups was as follows: t(11;14) vs no t(11;14)-50.0% vs 44.3% (p = .419); +1q vs no +1q-33.3% vs 52.1% (p = .026); hyperdiploidy vs no hyperdiploidy-41.7% vs 49.3% (p = .409); del(13q) vs no del(13q)-48.3% vs 48.1% (p = .978); and HR vs no HR: 56.3% vs 46.3% (p = .445). Similarly, +1q was the only subgroup with a significantly lower ≥ heme-VGPR rate (66.7% vs 83.1%; p = .023). At a median follow-up of 20.0 months, the median heme-EFS was 49.6 months (95% CI, 24.7-NR), and 2-year OS was 81.5% (95% CI, 75.8–86.1). Among cytogenetic subgroups, +1q was the only subgroup with a significantly worse heme-EFS compared to no +1q (median, 15.2 months vs NR, respectively; p = .044; Figure I).
Conclusion: In the Dara-VCD/Dara-VD frontline therapy era, +1q presence is linked to lower deep hematologic response rates and poorer heme-EFS compared to its absence. On the other hand, t(11;14) is no longer linked to worse outcomes in the daratumumab-era.
Abstract
Topic: Basic Science AL
Systemic light chain (LC) amyloidosis (AL) is a disease where organs are damaged by an overload of a misfolded patient-specific antibody-derived LC, secreted by an abnormal B cell clone. The high LC concentration in the blood leads to amyloid deposition at organ sites. Indeed, cryogenic electron microscopy (cryo-EM) has revealed unique amyloid folds for heart-derived fibrils taken from different patients. Here, we present the cryo-EM structure of heart-derived AL amyloid (AL59) from another patient with severe cardiac involvement. Its structure displays a stable core and two flexible segments adopting alternative conformations. Two confirmations are sterically incompatible and typically distributed on separate fibrils. Noteworthy, the fibril core harbours an extended constant domain fragment, thus ruling out the variable domain as sole amyloid building block. Surprisingly, the fibrils were abundantly concatenated with a proteinaceous polymer, here identified as collagen VI (COLVI) by immuno-electron microscopy (IEM) and mass-spectrometry. Cryogenic electron tomography (cryo-ET) showed how COLVI wraps around the amyloid forming a helical superstructure, likely stabilizing, and protecting the fibrils from clearance. Thus, here we report the first structural evidence of interactions between amyloid and collagen, potentially signifying a novel pathophysiological mechanism of amyloid deposits.
Abstract
Topic: Basic Science AL
This study extensively characterizes full-length (FL) and isolated domains; variable (VL) and constant (CL) of a patient-derived λ-light chain (LC) named AL55 whose fibril structures from the heart and kidney deposits were solved by our work, to unravel the factors influencing its amyloidogenic behavior. The X-ray structure of FL AL55 and data from hydrogen-deuterium exchange mass spectrometry unveil an open conformation of the two VLs in the dimeric structure, featuring a highly dynamic interface distinct from closed conformations observed in other known toxic LCs. This open structure enhances the VL’s susceptibility to proteolytic digestion, potentially facilitating amyloid formation from the isolated VL domain. Investigation into isolated domains confirms that the isolated VL is less structured, unstable, and dynamic in the CDR1 and CDR2 regions, correlating with its higher aggregation under in-vitro conditions. Additionally, unfolding, and refolding kinetic experiments provide in-depth insight into the slow unfolding rates of FL and CL but the fast-unfolding rate of VL which confirms the rate-limiting step in FL unfolding is stable CL domain. However, limited refolding due to the slow refolding rate of the VL domain confirms a shift of folding transition towards a misfolded conformation which might favor aggregation. Cytotoxicity assay in C. elegans shows soluble toxicity of FL AL55. Additionally, highly polymorphic amyloid fibrils formed by VL show that in-vitro formed fibrils are not truly representative of in-vivo deposited fibrils. Collectively, this research yields crucial insights into the structural and biophysical features influencing AL55 amyloidogenic behavior, presenting potential avenues for therapeutic intervention.
References showing past work in our lab on AL55 amyloid fibril structures extracted from the heart and kidney of an AL patient and the idea of doing current biophysical and structure work came from these two publications.
References
- Swuec P, Lavatelli F, Tasaki M, et al. Cryo-EM structure of cardiac amyloid fibrils from an immunoglobulin light chain AL amyloidosis patient. Nat Commun. 2019;10(1):1269.
- Puri S, Schulte T, Chaves-Sanjuan A, et al. The Cryo-EM structure of renal amyloid fibril suggests structurally homogeneous multiorgan aggregation in AL Amyloidosis. J Mol Biol. 2023;435(18):168215.
Abstract
Topic: Basic Science AL
Immunoglobulin light chain amyloidosis (AL) is caused by the aberrant production of amyloidogenic light chains (LC) that accumulate as amyloid deposits in vital organs including the heart and kidneys. Distinct LC sequences in each patient yield distinct amyloid structures. However different tissue microenvironments may also cause identical protein precursors to adopt different amyloid structures (polymorphic). To address the impact of the tissue microenvironment on the structural polymorphism, we extracted amyloid fibrils from the kidney of an AL patient (AL55) whose cardiac amyloid structure was previously determined by our group. Here we show that renal fibril’s 4.0 Å resolution cryo-EM structure is virtually identical to one reported for cardiac fibrils. This report provides the first structural evidence at the atomic resolution that LC amyloids that independently deposit in the different organs of AL patients are structurally homogenous.
Figure 1. Cartoon showing identical maps and structures of cardiac and renal amyloid fibrils of AL55 LC.
Reference
- Puri S, Schulte T, Bolognesi M, et al. The Cryo-EM structure of renal amyloid fibril suggests structurally homogeneous multiorgan aggregation in AL amyloidosis. JMB. 2023;435:16215. (IF 6.1), Selected as Journal Cover.
Abstract
Topic: Treatments of ATTR
Introduction: Patients with restrictive cardiomyopathy (CM) due to wtATTR unfortunately often respond poorly to standard heart failure medications. To date, there is limited data on SGLT-2 inhibitors in patients with cardiac amyloidosis. The aim of this study is to investigate the tolerability and efficacy of the SGLT-2 inhibitors empagliflozin and dapagliflozin in patients with cardiac amyloidosis.
Methods: Patients from our amyloidosis center with wtATTR-CM who were already treated with tafamidis 61 mg once daily were prescribed empagliflozin or dapagliflozin. Patients were assessed for NYHA class LVEF, global strain, NTpro- BNP as well as renal function and HbA1c at time of prescription as well as 3–6 month after.
Results: We included 19 patients (17 men) with an average age of 80 years. 5 patients were treated with dapagliflozin and 14 with empagliflozin. None of the patients reported a drug-related genitourinary infection. Mean left ventricular ejection fraction (LVEF) was 51% at baseline (SD 8,1) and remained stable after 3–6 months (mean 51%, SD 6,3). There were no significant changes in LVEF, global strain, NYHA stage, NTproBNP, creatinine or GFR levels and HbA1c.
Conclusion: Some patients with amyloidosis respond particularly well to SGLT2 inhibitor therapy. However, due to the small number of patients, we have not yet been able to detect any significant changes. Still, it is important to emphasize that no relevant drug-associated adverse events occurred in our cohort. Further studies are needed to investigate the effect of SLGT2 inhibitors in patients with cardiac amyloidosis in more detail.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis is currently treated with either stabilizers or silencers but given their different mechanism of action, there is interest in whether combination therapy has a role.
Aim: To compare the effects of combination therapy (tafamidis plus silencer) versus tafamidis monotherapy in transthyretin cardiac amyloid (ATTR-CM) patients.
Methods: A retrospective single-center cohort study of 155 patients (18 on combination therapy and 137 on tafamidis monotherapy) was conducted. Baseline biomarkers were measured at the start of the second medication for the combination therapy group and at tafamidis initiation for the monotherapy group. Death, cardiovascular-related hospitalizations (CVRH), composite death and CVRH, and all-cause hospitalizations, were compared and analyzed using Kaplan-Meier and Cox proportional hazard ratio models.
Results: At baseline, patients on combination therapy were younger (73 vs. 79 years), had a higher prevalence of variant type (44% vs. 16%), less symptom severity by NYHA scoring (5.6% in stages 3 or 4 vs. 40%), and slightly better eGFR (62 mL/min/1/0.73 m2 vs. 58 mL/min/1/0.73 m2) than those on tafamidis monotherapy. There were no significant differences in outcomes [MM1] between the two treatment groups as shown by Kaplan Meier graphs (). Furthermore, the multivariate Cox proportional hazard ratio, adjusted for the Columbia score, did not indicate any significant differences either.
Figure 1. Kaplan Meier curve graphs showing A. all-cause mortality B. Composite death and CVRH C. CVRH free time in months D. All cause hospitalization free time in months. Patients receiving combination therapy (N = 18) were marked as red line and the total cohort of patients receiving tafamidis (N = 137) were marked as blue line, p value derived from log-rank test.
Conclusions: This single center study comparing combination therapy and tafamidis monotherapy, suggests that combination therapy was not associated with benefits over tafamidis monotherapy in terms of mortality and cardiovascular hospitalization. Randomized trials are needed to determine the efficacy of combination therapy over monotherapy for ATTR-CM.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Light chain deposition disease (LCDD) is a systemic disease characterized by deposition of monoclonal immunoglobulin light chains in multiple organs, with kidneys the principal involved organ. We report here two cases of LCDD, which exhibited identical immunoelectron microscopy (IEM) characteristics in the kidneys and labial salivary glands (LSG).
Case report: Patient 1 was a 71-year-old woman presented with lower extremities edema. Serum free λ LC was elevated at 2308.08 mg/L with κ/λ ratio of 0.01. Bone marrow examination revealed 4% monoclonal plasma cell infiltration. We performed LSG biopsy for her suspected of amyloidosis. Under IEM, electron-dense, granular, nonfibrillar deposits along acinar basement membrane and capillary basement membrane were seen, and fine-grained substances aggregation were seen in some acinar cavities, with λ chain-restricted staining. Further renal biopsy was performed, and IEM confirmed electron dense deposits in the mesangial area, glomerular basement membrane and tubular basement membrane, with λ chain-restricted staining. Patient 2 was a 54-year-old woman presented with chest distress and edema. IEM examination of LSG showed electron dense deposits along capillary basement membrane, among focal interstitium, with κ chain-restricted staining. Further renal biopsy confirmed electron dense deposits by electron microscopy, with only κ chain staining by immunofluorescence. All the biopsies were negative for congo red staining. Both of them were diagnosed with LCDD after completing relevant examinations.
Summary and conclusion: The two cases demonstrate that LSG biopsy may be a quite simple and fast technique in the diagnosis of unsuspected LCDD, used as alternative to biopsy of the organs involved.
Abstract
Topic: Diagnosis AL
Background: A 63-year-old Black woman presented with progressive exertional dyspnea and chronic low back pain. The course and findings in her case are instructive.
Case report: Family history was notable for cardiac deaths. Echocardiogram demonstrated LV wall thickening and LVEF 45% with diastolic dysfunction. NT-pro BNP was 1691 pg/mL with troponin I 0.36 ng/mL. TTR sequencing detected a heterozygous V122I TTR variant. Serum free κ light chains were 664mg/L with a ratio of 16.5. Bone marrow studies showed 20–30% κ-restricted plasma cells with amyloid deposits (Figure 1A,B).
Tc99m-PYP scan was performed and was negative. MRI of the total spine showed ligamentum flavum (LF) thickening at L4-5 causing severe spinal stenosis; vertebral degenerative disease was minimal (Figure 1C). In both the abdominal fat and the LF, after L4-5 laminectomy and onlay arthrodesis, LC/MS confirmed AL κ-type; quantitative estimate of amyloid content in the LF was 5%. She was diagnosed with AL amyloidosis with stage 3B cardiac and spinal involvement and enrolled on the Aquarius trial (NCT05250973). She has achieved a partial hematologic response with a cardiac response, is now pain free and fully functional.
Conclusions: In patients with amyloidosis who have both a monoclonal gammopathy and a TTR variant, it is imperative to tissue type the amyloid and to employ diagnostic modalities such as Tc99m-PYP scans to deduce the correct diagnosis. ATTR and AL can both cause spinal stenosis with minimal degenerative changes in the spinal MRI. LF tissue must be stained for amyloid and, if present, typing must be sought.
Abstract
Topic: Treatments of AL
Aim: Overview of the treatment landscape for AL-A in Austria.
Methods: 210 AL-pts were recruited. Statistics were descriptive.
Results: 210 AL-A pts., 45.9% of pts. in AIDA, with (median follow up 7 years) were analysed. (others mostly wt-ATTR). 62.38%. of pts were male. AL-A pts. were younger (median age 66a vs. 78a) compared to wt-ATTR pts.
Organ involvement: heart (78.6%), kidneys (58.1%), GI-tract (23.3%), PNS (21.4%). Advanced Mayo stages predominant, resulting in a high number of pts. with severe to moderate renal and/or cardiac insufficiency (4.6%, 42.2% – 37.2%, 51.2%).
Treatments: 141/210 pts. received a 1st line of treatment (LoT), 35.5% a 2nd LoT, and 20,6% a 3rd or higher LoT, this attrition rate per LoT is above, the one for Myeloma. Median time to next treatment was 9.9 months. 54 pts. received a 1st LoT intending later ASCT, but only 54% received it. This compares inferior to Myeloma. The most frequently used therapeutic regimes were VCd-D (Andromeda) with or without Dara-maintenance resulting in a high rate of high-quality hematologic responses (CR + VGPR =51.9%). 90 pts. received 1st LoTs not intending later ASCT. Daratumumab based regimes were the most used, but treatment outcomes were much inferior (hematologic CR + VGPR =18.9%). Only 40 pts. received 2nd, LoT with modest results.
Survival: Median survival was found 45 months and inferior in advanced stages.
Take home-messages:
Efforts needed to improve early diagnosis
Necessity to establish disease modifying therapies
New therapeutics should be integrated in 1st LoTs preferentially.
Abstract
Topic: Pathology
Introduction: Transthyretin amyloidosis (ATTR) is a multisystem disease caused by the deposition of fibrillar protein in organs and tissues. ATTR genotypes and phenotypes are highly heterogeneous.
Methods: We present data on physical signs and symptoms, cardiac and neurological assessments and genetics in patients enrolled in the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo, Brazil.
Results: Six hundred-forty-four patients were enrolled, 505 with the variant form (ATTRv) and 139 with wild-type (ATTRwt). Sixteen different mutations were detected, the most common being Val50Met (48.3%) and V142Ile (40.8%). Overall, more than half of the patients presented cardiological involvement, and the difference in this proportion between the ATTRv and ATTRwt groups was significant (43.9 vs. 89.9%; p < .001). The neurological phenotype also differed between ATTRv and ATTRwt (56.8 vs. 31.7%; p < .001). The mixed phenotype was found in 25.6% of the population, without a significant difference between the forms of amyloidosis. A group of patients remained asymptomatic (10.4%), with a lower proportion of asymptomatic ATTRwt patients.
Conclusions: This study details the clinical and genetic spectrum of patients with ATTR in São Paulo, Brazil. This preliminary analysis highlights the considerable phenotypic heterogeneity of neurological and cardiac manifestations in patients with variant and wild-type ATTR.
Abstract
Topic: Pathology
Background: Accurate tissue typing of systemic amyloidosis is essential to provide appropriate therapy for individual patients. Objective: To get a real-life overview of typing strategies worldwide.
Methods: ISA performed an online questionnaire survey among ISA members. We prepared questionnaire sheets for referral institutions (Category 1; C1), institutions performing amyloid typing for internal requests only (Category 2; C2), and institutions outsourcing amyloid typing to referral institutions (Category 3; C3), respectively.
Results: Seventy-six institutions participated in this survey, including C1 (n = 33), C2 (n = 20), and C3 (n = 23) institutions. Various typing methods were available across the responding institutions, including immunohistochemistry (84.9% of C1/C2 institutions), immunofluorescence microscopy (43.4%), genetic analysis (77.4%), and mass spectrometric analysis (41.5%) (Figure). Most of the mass spectrometric typing analyses were performed in high-volume C1 institutions. Commercial antibodies were used worldwide for immunohistochemistry. C1 institutions in Europe and Asia and other institutions also used various in-house antibodies. 92.9% of institutions perform genetic analysis of TTR gene, followed by APOA1 (42.9%), FGA, GSN, LYZ (33.3%) and APOA2 (31.0%). Hierarchical referral flows (C2, C3 to C1 institutions, C1 to C1 institutions) of mass spectrometric analysis, immunohistochemistry, and genetic analysis were observed regionally and internationally. Globalization and centralization of referral flows were more prominent for mass spectrometric analysis.
Conclusion: Various methods were employed for the amyloid typing worldwide and hierarchical referral flows were observed regionally and internationally. These data provide an assessment of the current state, enabling improvement in capabilities of amyloid typing worldwide and enhance regional/international networks. Acknowledgements: We thank all the respondents.
Abstract
Topic: Basic Science AL
Light chain amyloidosis (AL) is characterized by tissue deposition of monoclonal immunoglobulin light chains (LC). According to serum immunofixation electrophoresis, 33% of AL patients have circulating monoclonal free LC, yet ∼40% features LC complexed to heavy chain (HC) forming intact monoclonal immunoglobulins, most commonly of IgG type. Physicochemical properties of free LCs, including enhanced dynamics in proteolysis- and amyloid-initiating regions, probably augment AL disease. To determine whether compromised stability of IgG assembly also contributes, we explored six recombinants intact IgG1 and corresponding l6 LC proteins: four with AL patient-derived sequences and two non-AL control sequences from the Observed Antibody Space database.
AL1 and AL2 sequences were from patients whose serum featured intact IgG, while AL3 and AL4 were from patients whose serum featured intact IgG plus free LC. Recombinant proteins were expressed in Expi293F mammalian cell system. LC were purified by ion-exchange and size exclusion chromatography and IgG by Protein A affinity chromatography. Protein identity and post-translational modifications were determined by mass spectrometry. Gel electrophoresis confirmed intact IgG formation. Protein folding was verified by circular dichroism. Protein thermostability was assessed by melting monitored by circular dichroism and turbidity; resilience to proteolysis by limited digestion; and disulfide link protection by beta-mercaptoethanol titration/SDS PAGE. Local protein dynamics was explored by hydrogen-deuterium exchange mass spectrometry. Amyloid formation was monitored by ThT fluorescence and electron microscopy. Despite differences in intact IgG thermostability, all IgGs showed similar resilience to proteolysis and S-S link reduction. These findings argue against the role of IgG instability in AL.
Abstract
Topic: Treatments of AL
Background: The arrival of proteasome inhibitors (PIs), and especially daratumumab, have represented a paradigm shift in the treatment of AL amyloidosis.
Aims: To compare hematological response (HR) and progression-free survival (PFS) according to induction therapies.
Methods: A retrospective study was designed including 90 AL amyloidosis patients treated between 1999 and 2023. Induction treatments were grouped into ≥2 new drugs (N = 19), 1 new drug-based schemes (N = 44) and chemotherapy (N = 25).
Results: Fourteen (17.9%), 23 (29.5%), 19 (24.4%) and 22 (28.2%) patients presented revised 2012 Mayo Clinic stage I, II, III and IV, respectively. Time to HR was shorter in patients treated with ≥2 new drugs-based schemes compared to those treated with 1 new drug-based schemes and chemotherapy (28 vs. 76 vs. 95 days; p < .001). Two or more new drugs-based schemes resulted in a rate of HR of 100%, compared to 75% in patients receiving 1 new drug-based schemes (p = .016) and 60.9% in chemotherapy (p = .002). Two or more new drugs-based schemes resulted in higher complete HR than 1 new drug-based schemes and chemotherapy (63.2% vs.36.4% vs. 13.0%; p = .054 and p = .002, respectively). With a median follow-up of 49 months, PFS was longer in patients receiving ≥2 new drugs-based schemes than in those treated with 1 new drug-based schemes and chemotherapy (not reached vs. 25.0 vs.10.0 months; p = .035 and p = .014, respectively) (Figure 1A). This clinical benefit was also shown in patients at stage III-IV (Figure 1B).
Conclusion: The addition of daratumumab to PIs improved HR and resulted into a significant benefit in PFS for all patients.
Abstract
Topic: Diagnosis AL
Introduction: Transthyretin amyloidosis (ATTR) is a rare yet impactful infiltrative disease. Utilizing DPD myocardial scintigraphy has emerged as a non-invasive, highly sensitive, and specific diagnostic tool for cardiac ATTR amyloidosis. However, instances exist where additional investigations reveal alternative conditions, such as AL amyloidosis. This study draws on experiences from the Onassis Cardiac Surgery Center and the monitoring center for infiltrative myocardial diseases at AHEPA's cardiology clinic.
Materials and Methods: Patients with suspected cardiac or extracardiac amyloidosis undergo Tc-99m DPD myocardial scintigraphy. Over 500 patients have been examined, and further diagnostic steps, including laboratory investigations and invasive techniques, are based on clinical and imaging findings (e.g. biopsy).
Results: Among 76 patients with positive myocardial scintigraphy (Grade 2 or 3 per Perugini scale), 8 were confirmed to have AL Amyloidosis during investigations into paraproteinemia. Three patients exhibited Grade 3 uptake, while the others showed Grade 2 or 2–3. Notably, one patient displayed diffuse radiopharmaceutical uptake in soft tissues without cardiac involvement, prompting κ and λ light chain analysis and immunostaining, leading to the diagnosis of AL amyloidosis.
Conclusion: While cardiac DPD scintigraphy plays crucial role in diagnosing cardiac amyloidosis from transthyretin, a positive result should not automatically imply ATTR amyloidosis. Crucially, differentiating between ATTR and AL amyloidosis is vital, given the significant implications for prognosis and therapeutic strategies. Laboratory exclusion of paraproteinemia is an essential step in the diagnostic algorithm for ATTR amyloidosis, especially since over 20% of patients with Grade 3 and 2 uptakes may have underlying AL amyloidosis.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: In this study, we explore the diagnostic potential of 99mTc-labeled pyrophosphate (PYP) and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) in cardiac amyloidosis, specifically distinguishing between light-chain (AL) and transthyretin (TTR) types.
Case presentation: A case of a 76-year-old woman with symptoms such as shortness of breath, peripheral congestion, and hand numbness revealed atypical echocardiographic and laboratory findings, indicating cardiac involvement. Despite concentric left ventricular hypertrophy, right ventricular hypertrophy, and severe diastolic dysfunction, the patient exhibited normal systolic function but impaired longitudinal function, indicative of cardiac amyloidosis.
A subsequent 99mTc-DPD study displayed an unexpected pattern of significantly increased soft tissue uptake in visceral, lung, and muscle regions, sparing traditionally affected organs. This unique uptake pattern was distinct from the typical distribution observed in both AL and TTR amyloidosis cases. The absence of cardiac uptake in single photon emission computed tomography (SPECT) images further emphasized this peculiarity.
Confirmation of AL amyloidosis was obtained through soft tissue biopsies and positive urine tests for Bence-Jones protein. The patient, at cardiac stage IIIb, responded well to a medication regimen including daratumumab, bortezomib, melphalan, and dexamethasone.
Conclusion: This case prompts consideration of 99mTc-DPD soft tissue uptake in unconventional areas as a potential indicator for AL-type amyloidosis, contrasting with the limited applicability of PYP due to its minimal soft tissue uptake. The absence of radiopharmaceutical mislabeling, or technical issues reinforces the reliability of these findings, underscoring the need for further investigation into the diagnostic utility of soft tissue uptake patterns in cardiac amyloidosis.
Abstract
Topic: Basic Science AL
Background: Light chain amyloidosis (AL) is characterized by the overproduction of immunoglobulin light-chains, which form insoluble aggregates and accumulate in vital organs. Diagnosing AL is difficult due to an overlapping clinical presentation with other types of amyloidosis and common diseases, which require distinct treatment. If untreated or treated incorrectly, AL can cause tissue damage, organ failure and death. Therefore, an accurate and rapid diagnosis is imperative.
Aim: To define the genetic properties and mutations of light-chains responsible for aggregation, fibril formation and organ damage to improve the diagnosis of AL.
Method: We developed a recombinant protein expression system to produce full length light-chains and a universal purification system. Light-chain variable sequences were identified from the Amyloid Light-Chain Database (AL-Base) and synthesized with kappa or lambda constant regions and a histidine tag as gene blocks for cloning into pCEP4. Germline light-chains were produced by reverting mutations to the germline sequence. Germline and mutated light-chains were expressed by human cell lines and purified from culture supernatant using his-tagged magnetic beads. The structure of light-chains was assessed using UV spectrometry and atomic force microscopy (AFM).
Results: Both kappa and lambda light-chain sequences achieved high yield protein production (milligram quantities). Native gel electrophoresis revealed light-chain monomers and dimers at varying ratios. UV spectrometry and AFM identified structural differences in mutated amyloid light-chains compared to germline sequences.
Conclusion: Our recombinant light-chain expression system can be utilized to identify amyloidogenic mutational signatures that could inform the development of genetic tests to improve diagnosis of AL.
Abstract
Topic: Treatments of AL
Background: Since the ANDROMEDA study excluded advanced patients from the trial, the efficacy and safety of DCyBorD therapy for AL patients with advanced stages remains unclear.
Objective: To clarify the efficacy and safety of DCyBorD therapy for systemic AL amyloidosis patients in advanced stages.
Patients and methods: All patients with systemic AL amyloidosis who were treated with DCyBorD therapy at our department were evaluated. The patients were divided into two groups: advanced group (stage 4 in Mayo stage 2012 or stage IIIb in revised cardiac stage 2013) and non-advanced group (other than those listed above). Efficacy (best hematological response) and safety (early death; death from any cause within 100 days after starting treatment) were retrospectively compared.
Results: Three in the advanced group and five in the non-advanced group were identified. Results of hematological response were as follows, in the advanced group, 1 patient achieved CR, VGPR in 1 patient, and unmeasurable in 1 patient, and in the non-advanced group, 2 patients achieved CR, VGPR in 2 patients, and 1 patient was not evaluable. Early death was observed in 66% of the advanced group and 0% of the non-advanced group.
Conclusion and discussion: Although DCyBorD therapy could introduce good hematological response even in the advanced group, high mortality was observed in this group. Further studies are needed to clarify whether DCyBorD therapy can significantly improve life prognosis in the advanced group.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Current staging systems for AL amyloidosis rely on a limited number of cardiac and plasma cell dyscrasia biomarkers, i.e. troponin, BNP/NT-proBNP and dFLC. However, treatment and disease-related outcomes within patient subgroups as defined by these systems can be heterogeneous. Leveraging a comprehensive panel of clinical parameters may better evaluate mortality risk.
We applied unsupervised machine learning methods to classify patients with AL amyloidosis from a large, longitudinal cohort at the Boston University Amyloidosis Center into novel patient subgroups. Our analysis included 2074 patients diagnosed between 1994–2023; 28 laboratory variables; and 31 clinical symptoms. Imputed baseline data were clustered using ConsensusClusterPlus, and the associations of these subgroups with mortality were evaluated.
Our clustering algorithm identified 3 novel subgroups of AL amyloidosis (Figure 1A,B): low-risk (n = 689), intermediate-risk (n = 822) and high-risk (n = 563) with distinct characteristics (Figure 1C) and overall survival (Figure 1D). The high-risk subgroup was distinguished from low/intermediate-risk subgroups by cardiac involvement. The intermediate-risk subgroup was distinguished by renal involvement (q-value <0.001, Fisher's exact); high proteinuria (median 7.0 g/24-h, q-value <0.001); and hypoalbuminemia (mean 2.4 g/dL, q-value <0.001) (Figure 1C). After adjusting for demographics and BU 2019 (BNP-based) cardiac staging, these novel subgroups were independently associated with mortality risk (p <0.01, Cox Proportional Hazards).
In conclusion, machine learning-based clustering allowed us to identify novel subgroups of patients with AL amyloidosis with clinically distinct phenotypes and mortality risks. We identified known high-risk patients with cardiac involvement, along with a renal phenotype that would otherwise not be captured by currently available staging systems.
Abstract
Topic: Prognosis ATTR
Introduction: Given the rise in ATTR-CA diagnoses and the correlated poor prognosis, identifying criteria that elevate mortality is crucial for early intervention. Numerous predictors have been outlined, and due to their clinical, epidemiological, and genetic diversity, analyzing each population is essential.
Objectives: To assess predictors linked to increased mortality in ATTR-CA.
Methods: This retrospective, single-center cohort study involved patients with confirmed ATTR-CA diagnosis via echocardiogram, scintigraphy, and BNP >150 pg/L. Univariate and multivariate Cox regression analyses were conducted to pinpoint mortality predictors, and Kaplan-Meier survival analysis was employed. A p-value <.05 was considered statistically significant.
Results: 94 patients were included. In a median follow-up of 66 months, there were 36 deaths (38%). The main baseline characteristics can be seen in figure 1. Although variables such as functional class, BNP, level of uptake on scintigraphy, ejection fraction, use of beta-blockers and diuretics were predictors in the univariate analysis, after multivariate assessment with the backward LR model, the only predictors were age at diagnosis, HR 1.086 (1.016–1.160), p = .015 and QRS duration, HR 1.019 (1.003–1.035), p = .018. When a dichotomous analysis was performed, an age >60 years and a QRS >135 msec were associated with higher mortality (figure 1).
Conclusions: Age >60 years and QRS duration >135 msec were predictors associated with worse prognosis in patients with ATTR-CA.
Abstract
Topic: Diagnosis ATTRv
Introduction: Hereditary transthyretin amyloidosis (ATTRv) arising from the TTR gene V30M variant (ATTRV30M) manifests in two distinct phenotypes: early-onset (before age 50 years) with polyneuropathy and late-onset (after age 50 years) with a mixed phenotype, encompassing neurological and cardiac manifestations (ATTR-CM). Comparative studies examining ATTR-CM in early and late ATTRV30M have typically involved patients’ post-diagnosis, with early-onset individuals being younger. This study aimed to compare ATTR-CM in early and late ATTRV30M at similar ages.
Methods: Medical records of 370 ATTRV30M patients were analysed (median follow-up: 3.6 years), summarizing data by 10-year age groups. Confirmed ATTR-CM was defined by a DPD scan (Perugini score ≥2), positive amyloid biopsy (Perugini score grade 1), or typical echocardiographic appearance (unexplained interventricular septum ≥13 mm).
Results: Among V30M carriers, 138 had early-onset polyneuropathy, 113 late-onset polyneuropathy, and 119 were asymptomatic carriers. ATTR-CM was confirmed in 16.7% of early-onset, 75.2% of late-onset, and 3.9% of asymptomatic carriers. ATTR-CM frequency increased with age. In a given age group, ATTR-CM degree was identical in early and late-onset groups (see Figure). Conversely, asymptomatic carriers showed lower ATTR-CM frequency (p = .001 in the 50–59 yo age group, p < 0.001 in the 60–69 yo age group). Late-onset patients had significantly higher life expectancy than early-onset patients (median survival: 83 yo and 62 yo, respectively; p < .001).
Conclusions: In a comparable age group, ATTR-CM extent is consistent in early and late-onset ATTRV30M. ATTR-CM penetrance rises with age, and both early and late-onset ATTRV30M exhibit a mixed phenotype. Neurological manifestations precede ATTR-CM onset.
Abstract
Topic: Diagnosis ATTRv
Introduction: Hereditary transthyretin amyloid cardiomyopathy (ATTRv-CM) results from mutated transthyretin deposits in the myocardium. Guidelines recommend screening ATTRv carriers for cardiomyopathy from the age of 60, but manifestations may occur earlier. This study aims to characterize TTR variants (TTRv) linked to early ATTRv-CM (before 60 years).
Methods: In this observational, monocentric study, 563 TTRv carriers were reviewed, including 220 with ATTRv-CM (Perugini ≥2 OR positive biopsy with interventricular septum ≥12 mm, CMR suggestive of cardiac amyloidosis, or Perugini 1).
Results: Of the 220 ATTRv-CM cases, 68 were identified before age 60 (31%). ATTRV30M was most frequently associated with early ATTRv-CM (32/68 pts). TTRv were classified according to the age of ATTRv-CM diagnosis (cf. Figure). TTRv exclusively linked to early ATTRv-CM included Thr49Ala, Ser50Arg, Ala36Pro, Glu54Leu, Ala19Asp, Gly53Glu, Phe33Leu, Phe64Ile, Arg34Gly, Glu42Asp, Gly47Arg, and Thr59Arg. Val122Ile was specifically associated with late ATTR-CM. Mean diagnosis age in the early group was 49 yo with 69% men. Compared to late ATTRv-CM, early cases had more neurological symptoms before 50 yo, more family histories of ATTRv, fewer cardiac symptoms, less positive bone scintigraphy, and a thinner interventricular septum. No differences were observed in electrocardiogram or CMR abnormalities.
Conclusions: ATTRv-CM may be commonly diagnosed before age 60 in TTRv carriers. In addition to known early associated variants, we report three new risk TTRv: Phe64Ile, Arg34Gly, and Glu42Asp. An early multimodal screening approach for ATTRv-CM appears reasonable for asymptomatic TTRv carriers.
Abstract
Topic: Prognosis AL
Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) with free light chain specific reagents (FLC-MS) is a novel method for the detection of a monoclonal serum FLC. FLC-MS negativity is associated with improved survival and organ response independent of the hematological response.1 We have further analysed the impact of FLC-MS negativity on survival, time to next treatment (TTNT) and organ response in a cohort who achieved a complete hematological response (CR). 487 patients underwent FLC-MS assessment at baseline and at 12-months post treatment. At the 12-month timepoint 164 (33.7%) patients achieved a CR by ISA criteria and 64 (39%) of these patients were FLC-MS negative. Median overall survival was not reached in either cohort (FLC-MS negative vs. positive) (p = .071). A cardiac response was seen in 22/32 (68.8%) vs. 35/64 (54.7%) (p = .269) and a renal response in 17/43 (39.5%) vs 22/62 (35.5%) (p = .446). 23/64 (35.9%) vs. 48/100 (48%) patients (FLC-MS negative vs. positive) received second line therapy. Median TTNT was 85 vs. 71 months (p = .027) respectively (). 4/64 (6.3%) vs. 14/100 (14%) (p = .121) required therapy within 24 months. For those with a dFLC <10 mg/L at 12 months median TTNT was 84 vs 71 months (p = .109) and median TNTT was NR vs. 75 months (p = .096) for patients with an iFLC <20 mg/L (FLC-MS negative vs. positive).
Figure 1. Time to next treatment – median TTNT was 85. Vs 71 months (p = .027 (FLC-MS negative vs. FLC-MS positive).
Overall patients who achieve FLC-MS negativity plus CR vs. CR alone have an improved survival and TTNT. There is a trend that organ response rates are also superior in FLC-MS negative patients.
Abstract
Topic: Treatments of ATTR
Introduction: Hereditary transthyretin amyloidosis (ATTRv) is an endemic disease in Brazil and presents enormous genotypic and phenotypic variability. Characterizing patients and discussing access to treatment is essential.
Methods: This is a cross-sectional evaluation, with descriptive analysis, including patients with pathogenic variants in the TTR gene. All patients were evaluated by a neurologist and cardiologist. Data regarding genotype, phenotype and access to treatment were collected from medical records. Patients who were taking medication in the last 3 months were considered to be undergoing treatment.
Results: A total of 73 patients were evaluated, median age of 51 years (IQR 40–66); 32 (43,8%) were symptomatic including 19 with isolated neuropathy and 13 with cardiopathy (12 with mixed phenotype and 1 with isolated cardiopathy). Genotypes Val30Met late and early-onset, Val122Ile and Ala39Asp occurred in 21 (65%), 4 (13%), 6 (19%) and 1 (3%), respectively; 25 symptomatic patients (78%) were undergoing treatment (19 with tafamidis 20 mg, 3 with tafamidis 80 mg and 3 with patisiran). Among the 7 (22%) untreated symptomatic patients, 1 had stage III neuropathy and 6 had a history of liver transplantation. Among 19 patients with neuropathy, 6 were in Coutinho stage II, of which 3 (50%) had access to patisiran. Among 13 patients with cardiopathy, 3 (23%) were using tafamidis 80 mg.
Conclusion: ATTRv Val30Met was the most frequent in our sample, as described in Brazil. Val122Ile variant presented with a mixed phenotype in our cohort. Early-stage neuropathy has easy access to treatment, while optimal treatment of heart disease and symptomatic post-transplant patients still represents a challenge.
Abstract
Topic: Pathology
Background: AA amyloid deposits consist mainly of serum amyloid A (SAA) derivatives and minor components such as apolipoprotein E (apoE). Although an association between gene polymorphism of SAA4 or apoE and amyloidogenesis has been reported, evaluation of the clinical data remains insufficient. Here, we investigated the SAA isotype present in these deposits, and considered the clinical implications of the data in relation to apoE4 polymorphism.
Materials and Methods: Thirty-seven patients with rheumatoid arthritis in whom AA amyloidosis had been confirmed by gastrointestinal biopsy were included. The biopsy specimens were subjected to LC-MS/MS for analysis of SAA derivatives. Phenotyping of apoE was performed using a commercially available kit. Clinical data were assessed by reference to patient records at the time of amyloidosis diagnosis.
Results: LC-MS/MS revealed SAA 1.1 derivatives in 8 patients (21.6%), 1.2/1.5 in 37, 1.3 in 30 (81.1%), and 1.4 in 27 (73.0%). Among 26 patients, the E2/3 apoE phenotype was detected in 2 patients (7.7%), E3/3 in 17 (65.4%), and E3/4 in 7 (26.9%). Patients with SAA1.1 derivatives showed a significantly shorter period from the onset of RA to amyloid detection than patients without SAA1.1. Additionally, patients with SAA1.3 had significantly lower levels of C3 and C4 than patients without SAA1.3. Moreover, in patients with apoE4, the ESR level was significantly higher than in patients without apoE4.
Conclusion: Polymorphism of both SAA and apoE may contribute to some features of AA amyloidosis.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
AA-amyloidosis is caused by the misfolding and aggregation of Serum Amyloid A in the extracellular matrix, leading to organ failure. The disease prevalence in captive cats and cheetahs was reported in the literature before, plausibly caused by horizontal transmission (Ferri et al. PLoS One 2023 10.1371/journal.pone.0281822). In cats, the kidneys, spleen, and liver are the most affected organs. This project focuses on cryo-EM structural analyses of ex-vivo samples extracted post-mortem from diseased cats, who therefore constitute a model for the pathology. Intriguingly, post-mortem analysis revealed an unparalleled distribution of AA amyloids present in the majority of the internal organs (Moccia et al. PLoS One 2023 10.1371/journal.pone.0293892). Here we report two AA-amyloid fibril structures extracted from the heart of a deceased cat, with multiple organ deposition. Interestingly, three different polymorphisms coexist in the same sample, named polymorphisms I, II, and III, which represent 80%, 15%, and 5% of the sample, respectively. The amyloid folds of the three polymorphisms are totally different, with polymorphisms I and II composed of two protofilaments and characterised by C2 symmetry, and polymorphism III composed of three protofilaments and presenting C1 symmetry. Moreover, the polypeptide arrangement is also extremely different between polymorphisms, and totally independent from cat, mouse, and human AA-amyloid structures previously deposited (Schulte et al. Nat Commun. 2022 10.1038/s41467-022-34743-2; Bansal et al. 2 Nat Commun. 2021 10.1038/s41467-021-21129-z; Liberta et al. Nat Commun. 2019 10.1038/s41467-019- 09033-z). The project ultimately aims to understand the molecular mechanisms underlying AA-fibril amyloidogenesis by comparing structures from different organs and species.
Abstract
Topic: Diagnosis ATTRwt
Introduction: The diagnosis of transthyretin cardiac amyloidosis (ATTR-CM) is complex, including numerous examinations and implicating different medical specialists. DIAM-ATTR survey aimed to obtain a snapshot of the current ATTR-CM diagnostic pathway via an electronic survey. Almost 70% of the 20.067 French healthcare professionals (HCPs) potentially implicated in ATTR-CM diagnosis, both public and private practice throughout France, were contacted. The ‘Réseau Amylose’ and ‘Filière Cardiogen’ were implicated. Levels of knowledge on ATTR-CM, use of recommended diagnostic algorithm, diagnostic pathway, as well as the difficulties encountered during diagnosis, overall and according to each specialty, were collected.
Results: 1264 physicians from 7 different specialties returned the survey. The levels of knowledge with respect to the signs and symptoms suggesting ATTR-CM differed between HCPs according to specialty, see figure 1. Regarding the diagnostic pathway, among the 719 HCPs diagnosing ATTR-CM, most adhere to the current diagnostic algorithm with almost all respondents performing bone scintigraphy and monoclonal gammopathy. However, some diagnostic examinations such as genetic testing were not systematically performed (59% to 93% depending on specialty). The healthcare pathway, as well as difficulties encountered for ATTR-CM diagnosis varied among specialities. The predominant difficulty pertained to confirming the type of amyloidosis by biopsy.
Conclusion: The French DIAM-ATTR survey shows that the recommended diagnostic algorithm is mostly followed although further HCPs education on clinical signs associated with ATTR-CM is needed. The survey identified several difficulties in the diagnostic pathway of the disease that should be overcome to improve ATTR-CM patients management.
Funding: Sponsored by Carely, founding by Pfizer.
Abstract
Topic: Prognosis ATTR
Background: Transthyretin amyloidosis (ATTR) manifests with cardiac and/or neuropathic symptoms; neuropathy can be assessed by the COMPASS-31 survey. We compared COMPASS-31 scores in patients with ATTRv (neuropathic/mixed phenotypes) to patients with ATTRwt and ATTRv-Val122Ile (both cardiac phenotype) and hypothesized that worse autonomic dysfunction, assessed by COMPASS-31, will associate with CV hospitalizations.
Methods: In this retrospective cohort study, COMPASS-31 scores (domains and overall) were compared across ATTR phenotypes. A receiver operating characteristic (ROC) analysis was conducted determining a COMPASS-31 score cut-off that identified ‘high’ autonomic neuropathy, associating scores with patient-reported neuropathy documented in medical histories. Using this cut-off, differences in clinical parameters and cardiovascular outcomes were assessed.
Results: 283 patients were studied. No significant differences in COMPASS-31 scores were found between cardiac and mixed phenotype groups. COMPASS-31 scores above 29 were defined as ‘high’, as per ROC analysis with outcomes based on reported presence of autonomic neuropathy documented in patient medical history. A ‘high’ score was associated with worse NYHA class, Columbia late-stage disease III (14.7% vs 1.9%, p = .01), and lower KCCQ scores (p < .01, overall score mean difference of 23.2 between low and high COMPASS groups, 95% CI: 16.5–30.0). Increased CV hospitalization risk was found in patients with high COMPASS-31 scores, after adjusting for age, sex, and Columbia score [HR =2.39 (95% CI: 1.17–4.89)].
Conclusions: COMPASS-31 scores do not significantly differ between those with distinct ATTR forms. Higher scores are associated with more advanced cardiac phenotype and with increased cardiovascular hospitalization risk.
Abstract
Topic: Diagnosis AL
Introduction: Older adults (≥65 years) are a high-risk group for amyloid light chain (AL) amyloidosis; however, estimates of prevalence and incidence of AL amyloidosis in this group are limited. Herein, we provide comprehensive estimates of overall and age-, sex-, and race-specific AL amyloidosis prevalence and incidence in older US adults using nationally representative data.
Methods: This cross-sectional retrospective cohort study identified beneficiaries ≥65 years with ≥1 inpatient or ≥2 outpatients claim for AL amyloidosis (ICD-10-CM diagnosis code E85.81) using Medicare 100% Research Identifiable Files. Inclusion criteria included continuous annual enrollment in Medicare fee-for-service (prevalent cases) and continuous enrollment and a one-year disease-free period (incident cases). Study outcomes included period prevalence per 100,000 per year (2018–2020) and incidence per 100,000 person-years (2019, 2020). Rates were stratified by age group (65–74, 75–84, ≥85), sex, and race.
Results: The prevalence of AL amyloidosis among older adults increased during the study period: 9.92 in 2018, 12.27 in 2019, and 14.01 cases per 100,000 in 2020. The incidence of AL amyloidosis increased slightly during the study period: 5.01 in 2019 to 5.12 cases per 100,000 person-years in 2020. The largest increase in estimates was seen among those aged 75–84 (prevalence) and ≥85 (incidence) years, males, and Black beneficiaries.
Conclusions: AL amyloidosis affects 14 per 100,000 older US adults. The prevalence and incidence of AL amyloidosis appear to be increasing, especially in those with increasing age, males, and Black beneficiaries. Further research focused on diagnostic patterns, clinical characteristics, and outcomes in these high-risk populations is needed.
Copyright for this individual abstract is: © 2024 Prothena. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Pathology
Background: Amyloidosis involving the gallbladder is rare and few studies have evaluated it systematically.
Objective: To determine the clinical, morphologic, and proteomic features of amyloid in cholecystectomy specimens.
Material and methods: Congo Red positive cholecystectomy specimens (N = 118) were identified. Detected amyloid deposits were analyzed using a clinical proteomics-based amyloid typing assay at Mayo Clinic. A pathologist scrutinized each amyloid proteomics profile and assigned a type based on the most abundant amyloidogenic protein. Clinical information was available for 10 patients. A feasible subset (N = 26) underwent morphological analysis for localization of amyloid within the gallbladder wall.
Results: We detected the following amyloid types: N = 63 ATTR (53.4%), N = 46 AL (39.0%), N = 4 AA (3.4%), N = 2 AApoAI (1.7%), N = 2 ALECT2 (1.7%), N = 1 EFEMP1 (0.8%). We detected known amyloidogenic mutations (p.Val142Ile variant) in 3 ATTR cases (3/63, 4.8%). Clinical information is summarized in . In the majority (70%), amyloid was an unexpected diagnosis first made on the cholecystectomy specimen. In 2 additional patients, cholecystectomy was performed prior to amyloid diagnosis but amyloid involvement was initially missed; following a diagnosis of cardiac amyloidosis, gallbladder amyloid involvement was retrospectively identified. Morphological analysis revealed all cases (n = 26) had amyloid deposition within perimuscular vessels.
Table 1. Summary of clinical information (N = 10).
Summary and conclusion: We identified 6 different types of amyloids involving cholecystectomy specimens, with AL and ATTR types accounting for 92.4%. The gallbladder may often be the first site of amyloid diagnosis. Careful evaluation of cholecystectomy specimens, in particular assessment of perimuscular vessels, can prevent delay in diagnosis of systemic amyloidosis.
Abstract
Topic: Treatments of AL
Introduction: In amyloid light chain (AL) amyloidosis, bortezomib-based therapy can grant satisfactory (hematologic complete remission and/or organ response) and durable response in some patients who may then not proceed to autologous stem cell transplantation (ASCT). We retrospectively compare the outcomes of the patients who deferred ASCT with the patients who conducted ASCT after induction treatment.
Methods: We reviewed the outcomes of newly diagnosed ASCT-eligible AL amyloidosis patients who received bortezomib-based chemotherapy at a referral center between 2013 and 2020. Patients with biopsy-proven, systemic, AL amyloidosis, aged between 18 and 70 years, N-terminal pro-brain natriuretic peptide (NT-proBNP) < 5000 pg/mL, troponin-T (TNT) < 0.06 ng/mL, high sensitivity TNT (hsTNT) < 0.075 ng/mL, and ejection fraction (EF) > 40% were included. Major exclusion criteria were concurrent multiple myeloma defined.
Results: Of total 27 patients who were eligible for ASCT, 24 patients who had induction chemotherapy were enrolled in this study. The best hematologic response rate after induction treatment was 66.6% (n = 16) complete remission (CR) and 33.3% (n = 8) very good partial remissions (VGPR). There was no specific difference of progression free survival (PFS) according to ASCT (p = .22). Median PFS did not differ with the presence of organ response (p = .86). However, patients who achieve hematologic CR after induction chemotherapy had favorable PFS compared with patients who achieve hematologic VGPR (p = .043). Swimmer's plot of each patient was shown in Figure.
Conclusions: In this study, we documented a high hematologic response rate with bortezomib based induction chemotherapy. We investigated if patients receiving bortezomib based chemotherapy could defer ASCT.
Abstract
Topic: Pathology
Objective: To analyze cases with suspected amyloidosis in the Amyloidosis Center at Kumamoto University.
Methods: We successfully established our web-based consultation system for amyloid typing in Japan by the support of the Global Bridges project. We performed histopathological, genetical and proteomic analyses in our center. For amyloid-typing, at first, we perform immunohistochemistry (IHC) using amyloid-specific antibodies panel in our center. If identifying amyloid precursor protein by IHC was difficult, we perform laser microdissection-liquid chromatography tandem–mass spectrometry (LMD-LC–MS/MS) analysis.
Results: We provided amyloidosis diagnosis support services for 2627 cases (tissue amyloid typing: 2168 cases, and genetic analyses: 459 cases) in Kumamoto University Amyloidosis Center from Jan 2021 to Jun 2023. We determined amyloid typing by our IHC in 1484 of 1569 cases. In our center, 61% (955 cases) was ATTR amyloidosis. Thirty-two % (504 cases) was AL amyloidosis. Seven % (109 cases) was other types of amyloidosis. We found different proportions of amyloid types in different tissue sites. Frequency of ATTR amyloidosis was higher than 60% in myocardium, synovium/ligament, and nerve/muscle tissues. Number of cases with ATTRwt amyloidosis was increasing year by year in our center.
Summary: We supported diagnosis of amyloidosis by means of histopathological, genetical and proteomic analyses in our center. Number of cases with ATTRwt amyloidosis was increasing year by year.
Abstract
Topic: Diagnosis ATTRwt
Background: The use of endomyocardial biopsy (EMB) after failed lip salivary gland biopsy (LSGB) is well described as the gold standard for diagnosis of ATTR. It is not known, however, how many patients with positive EMB will also have a subsequent positive LSGB.
Objective: To determine which patients who are EMB positive for ATTR will also have a positive LSGB performed thereafter.
Methods: All patients who underwent EMB in 2022–2023 for the diagnosis of cardiac ATTR were offered enrollment in the study involving subsequent LSGB by an oral surgeon trained in the procedure. Pathological analysis was performed on all samples including immunohistochemistry and Congo Red staining. All patients were treated for ATTR with tafamidis after initial confirmatory diagnosis.
Results: Five sequential patients who consented were enrolled in the study (see Table 1 for details). 242 ± 90 d elapsed between EMB and LSGB. Pyrophosphate (PYP) was positive in all participants with mean heart-to-contralateral lung (HCL) ratio of 1.95 ± 0.09 and mean intraventricular septal diameter (IVSD) of 16 ± 0.7 mm. LSGB biopsy was positive in only 1 patient (20%).
Conclusion: LSGB is not a substitute for EMB in most cases and even after 12 months of EMB positivity, LSGB can still be negative for amyloid staining and immunohistochemistry. This small number reinforces the use and strength of multimodality non-invasive imaging including echo and PYP scanning to help establish the diagnosis of cardiac ATTR. The use of tafamidis may also have attenuated the accumulation of ATTR in other tissues such as the salivary gland.
Abstract
Topic: Imaging
Subtopic: Cardiac
Introduction: Hereditary transthyretin amyloidosis (ATTRv) is described using neurological or cardiac references. Optimal screening for heart disease is often unavailable in our clinical practice.
Methods: Cross-sectional evaluation of ATTRv patients followed at a reference center of a university hospital in Brazil. Data regarding genotype, phenotype and cardiological screening were collected from medical records. We considered cardiac involvement when interventricular septum (IVS) ≥ 12 mm. Global longitudinal strain (GLS) by speckle-tracking echocardiography (2D-STE) was reduced when <20%. Confirmatory tests were pyrophosphate scintigraphy (PYP) Perugini score grade 2/3 or magnetic resonance imaging (MRI) with typical late gadolinium enhancement (LGE) pattern and increased extracellular volume (ECV).
Results: A total of 73 patients were evaluated; 13 (17.8%) patients presented IVS ≥12 mm (median 13 mm, IQR 12–17); GLS was reduced in 11 (84%) of 13 patients with IVS thickening. PYP was performed in 10 cases (77%) with positive results in all of them; MRI was performed in only in 5 (38%) patients, showing typical LGE and increased ECV (median 43%, IQR 36–58). Val122Ile occurred in 6 (46%), Val30Met in 6 and Ala39Asp in 1 patient. Mixed phenotype occurred in 12 (92%) where Val122Ile patients presented with milder neuropathy and were older than Val30Met (NIS score 10 [3–12] vs 71 [34–121] and 72 [65–84] vs 62 [52–71] years, respectively).
Conclusion: In ATTRv patients, 2D-STE screening with IVS ≥12 mm and GLS <20% was highly efficient for diagnosing cardiac involvement. Furthermore, Val122Ile genotype commonly presented with mixed phenotype associated with mild neuropathy in our sample.
Abstract
Topic: Prognosis AL
Background: Data on the incidence and risk factors for second malignancies are not available for patients with AL amyloidosis.
Aim: to describe the incidence and risk factors for the development of second malignancies among patients with AL amyloidosis.
Methods: The study included 417 consecutive patients, from the Department of Clinical Therapeutics, Athens. The analysis accounted for death due to AL and diagnosis of 2nd malignancy as competing events.
Results: median age was 65 years, 56% were females; heart and kidneys were involved in 76% and 65%; 16%, 44% and 40% were Mayo stage -1, -2 and -3. Treatment, across all lines, included bortezomib (95%), alkylators (75%) (mostly cyclophosphamide, melphalan in 21%, 5% high dose), lenalidomide (36%) and daratumumab (31%). Median follow-up was 5 years. A second malignancy, after AL diagnosis, occurred in 26 (6.2%) patients (solid tumors:23, hematologic:3 patients). The 5- and 10-year cumulative incidence of 2nd malignancy was 5.4% and 10.25%(figure). The 5-year cumulative probability was 8.9% in stage-1 patients (vs 10.5% for death), 5.4% for stage-2 (vs 50.2% for death) and 3.7% for stage-3 (vs 69.7% for death). There was no increased risk associated with the use of alkylators (neither cyclophosphamide or melphalan), lenalidomide or daratumumab. The 2nd cancer was the cause of death in 10/26 (38%) of affected patients.
Conclusion: second primary malignancies occur in ∼6% of AL patients; among those with low cardiac risk, who also have the longest survival, the 5-year cumulative risk was ∼9%. We did not find a significant correlation with the use of alkylators or other treatments.
Abstract
Topic: Prognosis AL
Introduction: Localized immunoglobulin light chain amyloidosis (Loc-AL) is an ultra-rare disease caused by the local deposition of misfolded AL fibrils. Limited data exist on patterns of disease presentation and long-term outcomes.
Methods: We reviewed 3108 patients with amyloidosis and selected 141 with biopsy proven Loc-AL at our institution between 1/2010 and 7/2023. Amyloid typing was available in all cases; mass spectrometry was performed in 60% of cases.
Results: The sites involved for 141 patients with Loc-AL are described in Figure 1. At presentation, 75 (53%) patients were symptomatic, in the other 47% patients Loc-AL was an incidental finding. Serum monoclonal protein (sMP) was detected in 29 (20%) patients, 12 of whom had serum light chain different from the localized light chain type. Abnormal free light chain ratio was reported in 17 (12%) patients, 6 of whom had a positive sMP. First line management included: observation (57%), surgical resection (38%), radiotherapy (2%), systemic therapy (7%), and topical therapy (3.5%). Seventeen patients (12%) required repeated interventions for local disease recurrence. No patient progressed to systemic AL. The 2- and 5-year local progression free survival rates were 93% and 78%, with no differences by disease site. The median overall survival (OS) was not reached; the 2- and 5-year OS rates were 99% and 92%, respectively.
Conclusion: Loc-AL has an excellent prognosis and does not progress to systemic AL disease. Observation and/or surgical removal are usually adequate initial approaches to manage Loc-AL, however, a small percentage of patients can relapse locally requiring repeated interventions.
Figure 1. Sites of Loc-AL
Abstract
Topic: Treatments of AL
Introduction: Daratumumab’s recent incorporation in the upfront treatment of light chain (AL) amyloidosis has led to daratumumab refractoriness early in disease course. Patients who experience relapse or have suboptimal response to daratumumab based therapy, have limited subsequent therapeutic options. This study aimed to evaluate the outcomes of venetoclax based therapy in t(11;14) positive AL amyloidosis after failure of daratumumab based therapy.
Methods: We reviewed all patients with AL amyloidosis at two centers between January 2016 and November 2023 who experienced disease progression or an inadequate response with daratumumab based therapies, and therefore were treated with venetoclax.
Results: Thirty-two patients were included. Daratumumab failure was due to inadequate response in 22 (69%) patients, hematologic relapse in 6 (19%), and both hematologic and organ relapse in 4 (12%). The hematologic overall response rate to venetoclax based therapies was 97%, with ≥ VGPR being 91%. Of the 26 patients with cardiac involvement, 15 (58%) achieved organ response. Of the 16 patients with renal involvement, seven (44%) achieved organ response. With a median follow-up of 22 months, median PFS and OS were not reached. The 12- and 24-month PFS rates were 85% and 65%, respectively. At data-cut-off, four patients had died, all from AL-related organ complications. The 12- and 24-month OS rates were 89% and 85%, respectively. Grade ≥3 adverse events occurred in 25% of patients, with 6% due to infections.
Conclusion: Venetoclax is effective in t(11;14) AL amyloidosis as salvage therapy after daratumumab failure in combination with dexamethasone or other plasma cell directed agents.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: High cardiac uptake of 99mTc-hydroxyethylene-diphosphonate (HDP) is closely associated with transthyretin (ATTR) cardiomyopathy.
Objectives: The main objectives were to assess the age-related incidence of incidental cardiac uptake and mortality in patients referred for whole body bone scintigraphy with HDP.
Methods: After ethical committee approval, 3169 bone scans in patients 50 years or older performed from 2013 through 2022 at Akershus University Hospital, a primary referral center, were reassessed for cardiac uptake. Survival after scintigraphy was registered with median follow up of 5 years.
Results: Unequivocal cardiac uptake, Perugini grade 1–3, was identified in 73 patients. Perugini grade 2 was found in 14 males and 2 females, grade 3 in 13 males and 0 females. After median follow up of 5 years 12/49 Perugini grade 2/3 were still alive ().
Table 1. Age and gender related to mortality.
Discussion: Short chain amyloidosis was not excluded in these patients, but Perugini grade 2/3 is strongly correlated with ATTR. The difference in age between the male and female population reflects the main indication, breast, or prostate cancer. However, also for benign indications less females were referred, resulting in only 154 female patients above 80 years of age being included.
Conclusion: Incidental cardiac uptake was found in 2.3%, preponderantly males. Incidence of Perugini grade 2/3 increased sharply after age 80, up to 9% after age 90. Nearly one in four Perugini grade 2/3, 9/36 Perugini grade 2 and 3/13 Perugini grade 3, were still alive at study close, median follow-up 5 years. So was also 19/44 patients Perugini grade1.
Abstract
Topic: Imaging
Subtopic: Echo
Introduction: Hematologic response to treatment for light chain cardiac amyloidosis (AL-CA) improves myocardial function and outcomes. We evaluated changes and prognostic value of echocardiographic myocardial deformation and work in response to treatment for AL-CA.
Methods: Sixty-one patients treated for AL were enrolled and underwent echocardiographic assessment at baseline and at 1-year. Patients were stratified according to hematologic response as complete or not complete responders.
Results: A significant reduction in median NT-proBNP, posterior wall thickness (PWT), and an increase in global work index (GWI) (1115 to 1356 mmHg%; p = .018) was observed at 1-year. Patients with complete response (CR) had a more pronounced decrease in intraventricular septum thickness (14.2 to 12.0 mm; p = .006), improved global longitudinal strain (GLS) (−11.6 to −13.1%; p for interaction =0.045), increased global constructive work (1245–1436 mmHg%; p = .008) and global work index (926 to 1250 mmHg%, p = .002) compared to non-CR. Furthermore, deltaGLS (ρspearman =0.35; p < .001) and deltaGWI (ρspearman = −0.32; p = .02) correlated with delta NT-proBNP. Importantly, patients with GLS and GWI response had a better prognosis (log-rank p = .048 and log-rank p = .007, respectively). After adjustment for Mayo stage, gender, and response status, deltaGLS (HR =1.404, p = .046 per 1% increase) and deltaGWI (HR =0.996, p = .042 per 1 mmHg% increase) were independent predictors of survival.
Conclusions: Complete hematologic response significantly improves left ventricular myocardial work indices, and their change is associated with improved survival in AL-CA.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Introduction: Although rehabilitation is an established part in the care of heart failure patients, data in those with cardiac amyloidosis CA).
Methods: We investigated the effects of exercise rehabilitation in two male wild-type transthyretin CA patients A and B (66 and 68 years of age, > 6 months on tafamidis). Exercise training regime comprised aerobic exercise (20–30 min on a cycle-ergometer, 30 sec effort and 30 sec rest, at 100% VO2peak) and strength training (2–3 sets, 10–12 repetitions, 60–70% 1 repetition maximum, leg extension/curls/chest press) for 36 sessions (3/week, 12 weeks). Aerobic capacity, strength and quality of life were assessed with cardiopulmonary exercise testing, 1 resistance maximum test and Minnesota Living with Heart Failure Questionnaire, respectively, before and after the program.
Results: Both patients completed the program without adverse events. For patient A, pre/post values were as follows: quality of life: 67/15, quadriceps strength: 35/42 kg, chest strength: 20/25 kg, VO2peak: 19.6/20.1 mL/kg/min and 1.47/1.51 L/min, anaerobic threshold: 12.5/11.0 mL/kg/min, maximum power: 80/100 watt. For patient Β, pre/post values were as follows: quality of life: 50/21, quadriceps strength: 15/18 kg, chest strength: 20/22 kg, VO2peak: 13.5/14.6 mL/kg/min and 0.74/0.79 L/min, anaerobic threshold: 9.3/8.9 mL/kg/min, maximum power: 35/45 watt.
Conclusions: An exercise rehabilitation program seemed to be safe, feasible and beneficial in terms of functional status and quality of life in two patients with CA. Validation in a larger cohort of CA patients is warranted.
Abstract
Topic: Treatments of AL
Background: Anti-BCMA chimeric-antigen-receptor T-cell (CART) is safe and efficient in multiple myeloma, yet questionable for AL-amyloidosis (AL). Previously we have shown the first proof of concept for CART in AL. Here we update our results on 12 AL patients receiving HBI0101, an academic anti-BCMA-CART.
Methods: Patients with relapsed/refractory AL with ≥3 prior lines were included. Most received 800 × 106 CART-cells.
Results: Most patients had cardiac involvement, with median proBNP of 2390 pg/L, including five with MAYO-stage-3a/3b. The median prior lines were 5 (3–10); almost all were ‘triple refractory’.
Safety: Grade 3–4 hematologic toxicities were frequent (8/12,67%), yet short and transient. Although cytokine-release-syndrome was observed in 10/12 (83%), it was mostly of grade 1–2. There were neither cases of neurotoxicity nor treatment-related deaths. Six patients developed AL-related organ deterioration, treated with supportive care, and subsequently resolved to baseline/better.
Efficacy: The overall hematological response rate was 91%, with median time to response of 26d, including 64% complete responses. Minimal residual disease negativity was measured in 6/10. Most importantly, rapid organ responses were observed in most patients. Duration of response was variable (1.5–25 m(ongoing)). Additional updated results will be presented.
Conclusion: In this largest cohort of AL patients treated with anti-BCMA-CART, we demonstrate acceptable and manageable toxicity even for advanced cardiac patients, and a remarkable hematologic efficacy, with prominent organ responses in most participants. While responses were quick and deep, survival was limited, implying for the usage of CART earlier in the course of disease. Anti-BCMA-CART may become a powerful tool to improve organ function and survival in AL.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Health-related quality of life (HRQoL) is a metric that reflects the patient's perception of their physical, mental, and social well-being. It is a crucial factor to consider when assessing the impact of systemic amyloidosis on patient's lives.
Objective: To describe HRQoL in patients with systemic transthyretin amyloidosis variant type (ATTRv) within a registry of individuals with amyloidosis.
Materials and methods: Cross-sectional study (2021–2023) of ATTRv amyloidosis patients from an Amyloidosis Registry. HRQoL, assessed through the EuroQoL 5D-3L (EQ-5D-3L), was described by the proportion of patients without problems, with moderate or severe problems in each domain. Visual analog scale was presented with mean and standard deviation or median and interquartile range, depending on the distribution. Finally, the HRQoL was compared with that of the general population.
Results: Twenty-four patients were included, with a median age of 51 years, predominantly women. Paresthesias (88%), weakness, and fatigue (79%) were prevalent symptoms. Nearly all patients experienced impairment in at least one EQ-5D-3L domain. Regarding specific domains, pain or discomfort was the most common complaint. The visual analog scale revealed a median of 52. Compared to the general population, individuals with ATTRv amyloidosis demonstrated a greater compromise in HRQoL across all EQ-5D-3L domains.
Summary and conclusion: The study reveals substantial impairment in HRQoL for ATTRv amyloidosis patients, emphasizing the need for targeted interventions. These results lay the groundwork for future research and guide clinical approaches to improve the well-being of this affected population.
Figure. Health-related quality of life assessed through Euro-QoL, differentiating each of the five domains in all patients and classifying them based on the time elapsed since diagnosis (less than 5 years and more than 5 year since diagnosis).
Abstract
Topic: Treatments of AL
Background: Two-thirds of patients with AL amyloidosis had renal involvement. First-line treatment consists of chemotherapy or chemotherapy followed by autologous stem cell transplantation (ASCT) to reduce light chain production. Renal response can be observed as early as 3 months after initiation of treatment.
Objective: Estimate the percentage of patients with AL amyloidosis and renal involvement who achieved renal response following first-line treatment.
Materials and methods: Closed retrospective cohort study. All consecutive patients belonging to an institutional registry and diagnosed with AL amyloidosis and renal involvement from 1 February 2003, until 30 April 2022, were included and followed for 12 months. The renal response rate was estimated as a percentage with a 95% confidence interval.
Results: Forty-three patients were included. Regarding first-line treatment, 70% (n = 30) of patients received chemotherapy exclusively and 30% (n = 13) received chemotherapy followed by ASCT. Complete renal response rates were 46% (29–63 95%CI) at 6-month and 43% (26–63 CI95%) at one-year follow-up. In contrast, 26% (13–43 CI95%) and 43% (26–63 CI95%) of patients encountered renal progression at 6-month and on-year follow-up, respectively.
When differentiating groups based on the received first-line treatment regimen, those who received chemotherapy followed by ASCT showed higher complete renal response at both 6 and 12 months, with lower renal progression at 12 months (Table 1).
Summary and conclusion: The first-line treatment improved renal function and reduced proteinuria in a significant percentage of patients. This was observed primarily in those who received chemotherapy followed by ASCT as initial treatment.
Abstract
Topic: Diagnosis ATTRwt
Introduction: Transthyretin cardiac amyloidosis (ATTR-CM) diagnosis is complex, including numerous examinations and medical specialists. DIAM-ATTR survey aimed to obtain a snapshot of the current ATTR-CM diagnostic pathway in France via an electronic survey. Almost 70% of the 20.067 French healthcare professionals (including 775 nuclear medicine physicians (NMp)), potentially implicated in ATTR-CM diagnosis were contacted. A section was dedicated to NMp to assess their current practices for cardiac scintigraphy with bone radiotracers and to evaluate access to cardiac bone scintigraphy (CBS).
Results: 1264 physicians from 7 different specialties including 148 NMp completed the survey. NMp worked in academic hospitals (35%), general hospitals (31%), or private practices (26%). 20% performed early acquisitions and 72% used SPECT acquisition. Perugini grading scale was carried out by 93% of the NMp but only 31% and 5% systematically performed heart/whole body or heart/mediastinum signal quantification, respectively. The overall median (Q1;Q3) delay to obtain results for cardiac bone scan was estimated at 2 weeks (2;4) compared to 4 (3;8) for cardiac MRI, and 2 (2;4) weeks for a biopsy. Among all physicians, 68% rarely or never faced difficulties for CBS. The main difficulties encountered were: appointment delay (60%), geographical distance (17%), interpretation (12%).
Conclusions: Access to CBS for French patients with a suspicion of ATTR-CM and quality of reports appear excellent showing good adherence to the recommended acquisition protocols and the widespread use of the Perugini grading scale. However, quantitative measurements were less performed underscoring room for improvement.
Funding: Sponsored by Carely, funding by Pfizer.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Tafamidis is a first-in-class TTR tetramer stabilizer that has shown efficacy in ATTR cardiac amyloidosis. It has also shown diagnostic utility in ATTR cardiac amyloidosis by bone scintigraphy and has recently begun to be used to determine response to treatment, but quantitative evaluation methods have not yet been established.
Objective: To determine the amyloid-reducing effect of tafamidis in patients with ATTR cardiac amyloidosis and the usefulness of RAVAT, a new three-dimensional amyloid quantification method using SRECT/CT.
Patients and Methods: Twenty patients who were treated with tafamidis and evaluated by 99mTc-pyrophosphate (PYP) scintigraphy were included in the study. We collected data such as, Age, sex, NYHA, myocardial markers (BNP, hANP, NT-proBNP, troponinT), echocardiographic data, in addition to 99mTc-PYP scintigraphy. In the 99mTc-PYP scintigraphy, a comparison was made between traditional methods (Perugini score and H/CL score) and RAVAT.
Results: Patient data before and after tafamidis treatment for an average of 1.5 years of treatment could be compared. No obvious significant differences were found in myocardial markers or echocardiographic data. On the other hand, 99mTc-PYP accumulation was significantly reduced by tafamidis in both conventional analyses and RAVAT. In the conventional analyses, an increase in accumulation after treatment was observed in several patients.
Conclusion and Discusstion: Tafamidis significantly reduced cardiac amyloid deposition evaluated by the 99mTc-PYP scintigraphy. RAVAT is able to quantitate three-dimensional amyloid burden and may be able to evaluate treatment response more accurate as compared to conventional methods.
Abstract
Topic: Treatments of AL
Background: AL amyloidosis (AL) with renal involvement confers significant morbidity. We characterised renal outcomes in these patients using U.S. EMR TriNetX database.
Methods: Adults with renal involvement receiving bortezomib or daratumumab at index (between July 2016-June 2023) were included. Exclusion criteria included prior AL treatment, myeloma, baseline end-stage renal disease (ESRD), dialysis or renal transplant. Palladini Renal Stages I, II and III were defined as none, one or both, respectively, of eGFR <50 mL/min and proteinuria >5 g/day. Graded renal response criteria (without ≥25% eGFR decrease) were: renal complete response (renCR, proteinuria ≤200 mg/day), renal very good partial response (renVGPR, >60% proteinuria reduction), renal partial response (renPR, 31–60% reduction) and renal non-response (renNR, ≤30% reduction).
Results: 265 patients with Palladini Renal Stage I (29.4%), II (51.3%) and III (19.3%) were treated with bortezomib-based (60%), daratumumab-based (8.3%) or bortezomib plus daratumumab-based regimens (31.7%). Of the bortezomib-based group (n = 159), 7.5% and 32.1% subsequently received daratumumab in addition to/instead of bortezomib, respectively.
17% of all patients had ≥25% 1-year eGFR reduction. 2-year progression to ESRD was 10% (Palladini Stage III at greatest risk (p < .001), Figure), and 2-year overall survival (OS) was 77%. There was no difference in OS by treatment or renal stage.
Among 180 patients with serial proteinuria data, best renal responses within 1 year were: renCR 1.7%, renVGPR 43.3%, renPR 8.9%, renNR 46.1%. There was no significant difference in renal response by treatment group.
Conclusion: Only half of patients were renal-responders and few achieved renCR, highlighting considerable unmet need in AL patients with renal involvement.
Abstract
Topic: Basic Science AL
Background: Transthyretin Amyloid Cardiomyopathy (ATTR-CM) is a rare, progressively debilitating, fatal disease. With no specific treatment available before 2018, ATTR-CM is still often under-diagnosed and reliable epidemiological data are still needed on this disease.
Objective: To estimate the annual incidence of ATTR-CM in France between 2011 and 2021 and describe characteristics of incident patients.
Material and methods: We used the French nationwide claims database. As there is no specific ICD-10 marker code for ATTR-CM, diagnosis required both amyloidosis (identified by E85 code or tafamidis delivery) and cardiovascular condition (identified by ICD-10 codes of heart failure, arrhythmias, conduction disorders or cardiomyopathies), not necessarily reported at the same visit. Patients with probable AL-form or AA-form of amyloidosis were excluded.
Results: Between 2011 and 2021, 15,269 patients with incident ATTR-CM were identified. For 13,737 of them, the cardiovascular condition was coded first, and amyloidosis in second. Incidence rates increased from 0.6/100,000 person-years in 2011 to 5.1/100,000 person-years in 2021 (p < .001), reaching 3443 new cases in 2021. Crude incidence varied according to the Department of residence. Sex ratio (M/F) increased from 1.56 in 2011 to 2.14 in 2021. Median age at diagnosis was 83.0 years (85.0 for women and 83.0 for men), and increased over the period (81 years between 2011 and 2017, to reach 85 years in 2021)
Summary and conclusion: We observed an increase in ATTR-CM incidence over the study period, consistent with an improvement in ATTR-CM diagnosis in recent years.
Support and funding: This study was sponsored by Pfizer.
Abstract
Topic: Treatments of ATTR
Background: Tafamidis is the only currently approved treatment of transthyretin amyloid cardiomyopathy (ATTR-CM). Recently, acoramidis, was shown to reduce cardiovascular-related hospitalizations (CVRH) compared to placebo. However, there are no evidence directly comparing the two stabilizers.
Aim: To compare the long-term effect of tafamidis vs acoramidis in patients with ATTR-CM.
Methods: This a retrospective cohort study including 10 patients receiving acoramidis treatment for a median of 60 (range 38–64) months and compared to patients taking tafamidis (n = 137). Acoramidis treated patients (n = 10) were matched 1:3 to tafamidis treated subjects (n = 30) on age, gender, race, genotype, and disease severity based on Columbia score. We compared outcomes by Kaplan Meier analysis and by a hierarchical endpoint of all-cause mortality followed by CVRH using the win ratio.
Results: Among the entire cohort, there was a trend for better survival (log-rank test =0.13, Figure A) with acoramidis. Hierarchical analysis in the total cohort, resulted in a win ratio of 2.6 (1.31–5.16) favoring acoramidis (p = .006, Figure B). Among the matched cohort, all-cause mortality did not differ between the two-groups (log-rank test =0.42, Figure C). Hierarchical analysis in the matched cohort revealed a win ratio of 1.88 (0.74–4.77) in favor of acoramidis (p = .18, Figure D).
Conclusions: The present study, limited by a small sample size, showed for the first time that long term treatment with acoramidis compares favorably to tafamidis in terms of survival and CVRH.
Abstract
Topic: Diagnosis AL
Introduction: Amyloidosis is an acquired or hereditary disease that arises from deposition of insoluble beta-sheet fibrillar protein. While these aggregates can be either localized or systemic, accumulation in cardiac tissue can cause serious complications such as cardiomyopathy. Carpal tunnel syndrome due to amyloid deposition in transverse carpal ligament (TCL) may serve as an early sign of cardiac amyloidosis by 5–9 years.
Methods: Single center, retrospective review of patients who have undergone carpal tunnel surgery for TCL release from 5/2019 to 12/2023 was collected. Total of 46 patients were analyzed for presence of amyloidosis in tissue sample analysis and related cardiac follow up if positive for amyloid in TCL.
Results: The mean age was 65.3 years of age with 17 females and 29 males in this study. 11 (23.4%) patients resulted positive for amyloid staining, composing of 1 female and 10 males with mean age of 73.1 years. Out of 11 patients with positive results, 3 (27.3%) patients had bilateral carpal tunnel surgeries. Among 8 patients with data on cardiology work up for amyloidosis available, one (12.5%) had grade I pyrophosphate (PYP) uptake concerning for cardiac amyloidosis while others were negative at this time.
Conclusions: TCL analysis from carpal tunnel surgery can be an effective and simple tool for screening for amyloid deposition that can aid in early detection of serious amyloidosis such as cardiac amyloidosis. Recognizing the significance of the positive results from amyloid testing can improve patient care via close cardiology follow-ups.
Table 1 Patient demographics and amyloid testing data.
Abstract
Topic: Organ Transplant
Purpose: To review our center’s experience with heart transplant in patients with light chain cardiac amyloidosis (AL-CA).
Methods: We retrospectively analyzed all patients who underwent heart transplant at the Cleveland Clinic for heart failure due to AL-CA and reviewed demographics, clinical characteristics, post-transplant hospitalizations, and survival data as of 1st October 2023.
Results: The cohort comprised a total of 20 patients, 16 with lambda and 4 with kappa AL-CA. Median age at diagnosis was 58.6 and median age at transplant was 59.7 years. Median time from diagnosis to transplant was 4.9 months (SD: 19.0). Six patients (30%) had a heart-kidney transplant, and only 4 patients underwent subsequent autologous stem cell transplant (ASCT). Median follow-up was 33 months (range: 6–111), with 19 of 20 patients alive at the time of data extraction. Nine patients (45%) had at least one hospitalization post-transplant. Four patients had an episode of early 2R cellular rejection, and one patient had early 2R cellular and antibody mediated rejection; all of which were successfully treated. No patients developed recurrent AL-CA in the allograft or other organs thus far. One patient expired at 6 months following transplant due to an opportunistic infection.
Conclusions: Heart transplantation for patients with AL-CA in our center showed promising outcomes, suggesting it as a viable therapeutic option for select patients. In the current era of improving medical therapies for AL-CA, ASCT may not be routinely needed. Longer-term analyses are warranted to confirm these findings and refine patient selection and post-transplant management strategies.
Abstract
Topic: Organ Transplant
Purpose: To review our center’s experience with heart transplant in patients with transthyretin amyloid cardiomyopathy (ATTR-CM).
Methods: We retrospectively analyzed all patients who underwent heart transplant at the Cleveland Clinic for heart failure due to ATTR-CM. Patient demographics, clinical characteristics, hospitalizations, and survival data were extracted.
Result: The cohort comprised a total of 32 patients. Median age at diagnosis was 65 and median age at transplantation was 67 years. Eight patients had wild-type (wtATTR) and 24 had hereditary ATTR-CM (hATTR), with Val122Ile being the predominant variant (19 patients). Five patients (4 hATTR and one wtATTR) had a heart-kidney transplant and 2 (hATTR) had a heart-liver transplant. Post-transplant, 16 patients were treated with Tafamidis, and 3 hATTR patients with gene silencers. Median follow-up was 3.3 years with 25 of 32 patients alive at time of data extraction. Estimated survival rates were 97% and 84% at 1 and 3 years respectively. Causes of death (7 patients) included COVID, sudden death, acute liver rejection, infection, graft dysfunction, and renal failure. No patients had recurring amyloid in the allograft. One patient with Val122Ile followed up for 15 years developed autonomic and peripheral neuropathy, and one with Thr60Ala developed severe autonomic neuropathy.
Conclusions: Heart transplant for patients with ATTR-CM in our center showed promising outcomes, suggesting it as a viable therapeutic option for select patients. Longer-term analyses are warranted to confirm these findings and refine patient selection and post-transplant management strategies.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: The valine-to-isoleucine substitution at position 122 (V122I) is a genetic mutation in the transthyretin (TTR) gene found in 3–4% of individuals of West African descent which can lead to hereditary transthyretin amyloidosis (hATTR).
Case: A 68-year-old African American male with stage D heart failure secondary to hATTR cardiomyopathy (V122I) underwent orthotopic heart transplantation. One-year post-transplant the patient experienced progressive symptoms of polyneuropathy and hematuria. Cystoscopy showed friable bladder tissue and biopsy confirmed high grade papillary urothelial carcinoma (Figure 1A). Congo red staining revealed ATTR amyloid deposits (Figure 1B and 1C). Given plan for ileal conduit urinary diversion, he underwent colonoscopy with gastric and duodenal biopsies showing ATTR amyloid.
Decision-making: The patient was initiated on stabilizer therapy with Tafamidis. He successfully underwent radical cystoprostatectomy with ureteral diversion. Given the presence of hereditary ATTR polyneuropathy with diffuse extracardiac involvement (GI, bladder, nerves), he was approved for silencer therapy with patisiran. He continued to undergo routine transplant surveillance with no evidence of amyloid deposits on endomyocardial biopsies.
Conclusion: It is important to recognize that ATTR amyloidosis is a multi-system disease. Although rare, ATTR amyloid can deposit in the bladder and mimic urothelial carcinoma on gross examination and presentation. This case highlights the importance of suspecting amyloidosis involvement of any organ in the appropriate clinical context. In this case, our team requested Congo Red staining of the bladder specimen given the known hATTR history. This has important treatment implications, although the exact role of stabilizer therapy vs. gene silencers in bladder involvement is unclear.
Abstract
Topic: Diagnosis ATTRwt
Background: Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) predominantly affects older adults and is currently categorized as a rare disorder. No screening study has ever been conducted in the general population.
Methods: General practitioners in the area of Pisa (Tuscany, Italy), offered screening for ATTRwt-CA to all their patients aged between 65 and 90 years, until 1000 individuals started the screening. The following red flags were searched: an interventricular septal thickness ≥12 mm, any echocardiographic, electrocardiographic, or clinical indicators of CA, or high-sensitivity troponin T ≥ 14 ng/L. Individuals with at least one red flag (n = 346) were invited to undergo bone scintigraphy and the search for a monoclonal protein, with 216 agreeing.
Results: Four patients were diagnosed with ATTRwt-CA. One woman and one man, aged 79 and 85 respectively, exhibited intense cardiac tracer uptake (grade 3), left ventricular (LV) wall thickening, diastolic dysfunction ranging from grade 2 to 3, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels exceeding 1000 ng/L. The other two patients, a 74-year-old man and an 83-year-old woman, demonstrated a grade 2 tracer uptake, increased LV septal thickness, but preserved diastolic function, and NT-proBNP levels below 300 ng/L. All patients reported mild dyspnea on effort. The prevalence of ATTR-CA in individuals aged 65–90 years was calculated to be 0.46% (i.e. 4 out of the 870 subjects completing the screening, including 654 who did not meet the criteria for Step 2 and 216 who advanced to Step 2).
Conclusions: ATTRwt-CA has a prevalence of 0.46% in elderly individuals from the general population.
Abstract
Topic: Diagnosis ATTRv
Background: MScan-motor unit number estimation (MScan-MUNE) was evaluated to estimate axonal loss, as a potential biomarker of transition to symptomatic disease in hereditary transthyretin amyloid polyneuropathy (ATTRv-PN).
Methods: Ulnar MScan-MUNE was undertaken in 19 prospectively recruited patients carrying ATTR variants, and parameters were compared between patients with large fibre neuropathy (LF+), those without (LF-), and healthy controls. Relationships to clinical severity scores were determined and cut-off values calculated.
Results: Compared to healthy controls, despite similar motor amplitudes, LF + patients had fewer motor units (51.8 ± 35.8 vs 102.8 ± 42.2, p = .003) and large units (11.3 (9.4–15.6) vs 25.4 (18.3–33.8), p = .007), and greater mean unit amplitude (146.8 ± 65.5 vs 99.7 ± 37.4, p = .005). LF- patients had greater mean unit amplitude than healthy controls (117.0 ± 4.4 vs 84.2 ± 30.0, p < .05). MScan-MUNE and the number of large units reduced with increasing disease severity (all p < .05). A cut-off of 76 motor units could distinguish asymptomatic individuals (Polyneuropathy Disability (PND) Score 0) from symptomatic (PND 1 or greater; AUC 0.80 (0.54–1.00)) with sensitivity of 100% and specificity of 78.6%.
Conclusions: ATTRv-PN is associated with progressive axonal loss, measured by MScan-MUNE, that correlates with disease severity. Motor unit loss occurs early in ATTRv-PN, masked by re-innervation, which preserves CMAP amplitudes. MScan-MUNE may be a promising targeted biomarker of transition to symptomatic disease in ATTRv-PN.
Abstract
Topic: Diagnosis ATTRv
Background: Neurofilament light chain (NfL) has emerged as a sensitive biomarker in hereditary transthyretin amyloid polyneuropathy (ATTRv-PN). We hypothesise that NfL can identify conversion of gene carriers to symptomatic disease, and guide treatment approaches.
Methods: Serum NfL concentration was measured longitudinally (2015–2022) in 59 presymptomatic and symptomatic ATTR variant carriers. Correlations between NfL and demographics, biochemistry and staging scores were performed as well as longitudinal changes pre- and post-treatment, and in asymptomatic and symptomatic cohorts. Receiver-operating analyses were performed to determine cut-off values.
Results: NfL levels correlated with examination scores (CMTNS, NIS and MRC; all p < .01) and increased with disease severity (PND and FAP; all p < .05). NfL was higher in symptomatic and sensorimotor converters, than asymptomatic or sensory converters irrespective of time (all p < .05). Symptomatic or sensorimotor converters were discriminated from asymptomatic patients by NfL concentrations >64.5 pg/mL (sensitivity =91.9%, specificity =88.5%), whereas asymptomatic patients could only be discriminated from sensory or sensorimotor converters or symptomatic individuals by a NfL concentration >88.9 pg/mL (sensitivity =62.9%, specificity =96.2%) However, an NfL increment of 17% over 6 months could discriminate asymptomatic from sensory or sensorimotor converters (sensitivity =88.9%, specificity =80.0%). NfL reduced with treatment by 36% per year and correlated with TTR suppression (r = 0.64, p = .008).
Conclusions: This data validates the use of serum NfL to identify conversion to symptomatic disease in ATTRv-PN. NfL levels can guide assessment of disease progression and response to therapies.
Serum Neurofilament light chain (NfL) increases with disease severity (A,B) and with transition to symptomatic disease (C,D). A,B: Baseline logged neurofilament light chain (log(NfL), pg/mL) increases with increasing peripheral neuropathy disability (PND) scores (A) and Familial amyloid polyneuropathy (FAP) stage (B). Black circles indicate raw data values. C-D: Longitudinal evaluation of logged neurofilament light chain (log(NfL), pg/mL) levels according to clinical group as assessed by generalized linear mixed model. C: Differences in log(NfL) over time can be distinguished by group status demonstrating significant increases in symptomatic and motor converters irrespective of time, when compared to asymptomatic and sensory converting patients, D: Longitudinal changes (years) in log(NfL) according to group status, where A: Asymptomatic (yellow), SC: Sensory converters (red), MC: Sensorimotor converters (aqua) and S: Symptomatic (green) groups.
Individuals were characterized as asymptomatic (A) if they remained asymptomatic throughout the follow-up period with PND 0, MRC 70 and NIS 0. Symptomatic individuals (S) had evidence of a symptomatic neuropathy at baseline and throughout the follow-up period, with NIS >5 or MRC score <70 and PND score of 1 or above at baseline. An individual was categorized as a sensory converter (SC), if they were asymptomatic at initial review and during follow-up, they transitioned from PND or FAP scores of 0 to 1, NIS 0 to >0 and maintained an MRC score of 70. Sensorimotor converters (MC) were individuals who were asymptomatic at baseline and converted from a PND score of 0 or 1 to a score of ≥2 and developed muscle weakness (MRC score <70).
Abstract
Topics: Diagnosis ATTRv
Objectives: Hereditary Transthyretin amyloidosis (ATTRv) is characterised by progressive sensorimotor and autonomic neuropathy, and cardiac failure. We aim to describe the spectrum of ATTRv neuropathy in Australia.
Methods: A retrospective analysis of ATTRv patients attending Australian Amyloidosis Network clinics between 2007–2022 was performed. TTR variants, clinical features and treatments were evaluated.
Results: 161 individuals were identified (62% NSW/ACT, 20% QLD, 12% VIC/TAS, 4% WA, 2% SA). Average age was 59.4 years (range 21.5–91.4). 53% were male. 37% were presymptomatic (average age 52.7 years, range 21.5–71.0). 24 genetic variants were identified, including Thr60Ala (31%), Val30Met (23%), Val122Ile (12%), Ala97Ser (6%), Glu89Gln (5%).
The diagnosis rate has increased from 2 p.a in 2011–13 to 5 p.a in 2015–17, and 12 p.a in 2020–22. The average time to diagnosis was 3.8 years (range 1–15). 13 asymptomatic individuals developed symptomatic disease over an average 2.3 years (range 0–8). 40% had neuropathic-predominant disease, 32% cardiac, 25% mixed cardiac and neuropathic, and 3% had other organ-predominant disease. Of the 130 living individuals 45% had a PND score of 0, 22% PND1,10% PND2, and 9% PND3a or above. Similarly, 53% of individuals had a FAP0, 31% FAP1, 15% FAP2 and 1% FAP3. Of individuals with PND0–2, only 22% were on highly efficacious treatments, all via clinical trial or compassionate access scheme.
Conclusions: Our study is the first to demonstrate the spectrum of ATTRv in Australia. Affordable TTR genotyping and access to highly efficacious novel therapies remain substantial unmet needs in this population.
Abstract
Topic: Prognosis AL
Background: Cardiac involvement by immunoglobulin free light chain deposition accounts for patients’ mortality in AL amyloidosis. Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with an increased cardiovascular risk compared to the general population. However, the prevalence and prognostic impact of CHIP in AL amyloidosis are unknown.
Methods: Demographics and clinical characteristics of AL amyloidosis patients who underwent next-generation sequencing on a bone marrow sample at DFCI from January 2018 to April 2023 were collected. The variant allele fraction to define CHIP was set at 2%. Major organ dysfunction progression-free survival (MOD-PFS) was the primary outcome. Univariate Cox regression analysis was performed. The study was IRB approved.
Results: Seventy-six patients met inclusion criteria. CHIP was identified in 16 patients (21%) versus an age-standardized incidence rate of 6%. DNMT3A was the most frequently involved gene (7/16, 44%) (Figure 1). The presence of CHIP was strongly associated with a lower Palladini renal stage in patients with renal involvement (p = .001), and, in those with available FISH, with t(11;14) (11/13, 85%, versus 15/41, 37% in patients without CHIP, p = .004). Median follow-up time was 25 months with 30 patients (39%) developing MOD or progressive disease. In univariate analysis, CHIP was not associated with shorter MOD-PFS (hazard ratio 0.998, 95% CI 0.38–2.64).
Conclusions: This is the largest series to date reporting on prevalence and impact of CHIP in AL amyloidosis patients. We identified an association between CHIP and t(11;14) and a lower Palladini renal stage. Prospective studies are needed to validate these findings.
Abstract
Topic: Prognosis ATTR
Introduction: Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by progressive cardiac dysfunction.
Objective: To describe and compare ATTR-CM classified into three groups HFpEF (≥50%), HFmrEF (41%–49%), and HFrEF (≤40%). Methods. Retrospective cohort in patients with ATTR-CM defined by an end-diastolic interventricular septal wall thickness ≥12 mm, cardiac scintigraphy with uptake grade ≥2 (Perugini scale) or evidence of transthyretin amyloid on cardiac biopsy. Patients with other cardiomyopathies were excluded. The collected data were analyzed using SPSS statistical software, version 23.
Results: 83 patients were included (mean age 74.2 years), with a mean follow-up time of 65.7 ± 42.3 months. The distribution for HFpEF, HFmrEF and HFrEF was 55.4%, 19.3% and 25.3%, respectively. There was no significant difference in the ATTRv form among the groups (p = .660), although there was a statistical difference in the p.Val142Ile variant, with a lower prevalence in the groups with HFpEF and HFmrEF and higher in the group with HFrEF (8.7%, 12.5% and 47.6%; p = .035). BNP was less elevated in HFpEF and HFmrEF than in HFrEF, showing a significant difference (361.0 pg/mL, 350.0 pg/mL and 675.5 pg/mL, respectively; p = .035). On the ECG, LBBB was more frequent in HFmrEF (p = .026). On the echocardiogram, the interventricular septum was higher in HFrEF, as well as mitral and tricuspid insufficiency, with statistical difference when compared with HFpEF and HFmrEF. In the survival curve, the HFrEF had higher mortality when compared to the other groups (HR 0.24; 95% CI, 0.10–0.37; p <0.001).
Table 1. Characteristics of patients with transthyretin amyloid cardiomyopathy classified into heart failure with preserved, mildly reduce and reduced ejection fraction.
Conclusion: Our study demonstrated that patients with ATTR-CM with HFrEF has a worse prognosis.
Abstract
Topic: Treatments of ATTR
Objective: To assess the clinical utility of serum neurofilament light chain (sNfL) in patients with transthyretin-related amyloid cardiomyopathy (ATTR-CM) and the effect of tafamidis.
Methods: sNfL levels were systematically measured in serum samples using Uman Diagnostics ELISA assay (Quanterix). sNFL levels were compared in variant vs wild-type ATTR-CM, by presence of peripheral neuropathy (PN) symptoms, and by tafamidis treatment arm. Patients with significant ATTR-related polyneuropathy who had an indication for silencer therapy were excluded.
Results: 69 patients (median age 77.5 years (Interquartile Range: 72.3–82.9 years); 5.8% female; 13.0% vATTR-CM; 47.8% with symptoms of PN) were included in the analysis. There was no difference in sNfL between patients with vATTR-CM vs wtATTR-CM (42.3 ± 7.2 vs 38.3 ± 3.7 pg/mL, respectively; p = .675) or in those with or without PN symptoms (40.8 ± 6.0 vs 37.3 ± 3.5 pg/mL, respectively; p = .609). There was also no difference in sNfL level in tafamidis-treated vs untreated patients (38.4 ± 5.7 vs 39.3 ± 3.8 pg/mL, respectively; p = .904). In 17 patients with available paired pre-tafamidis and on-tafamidis samples, there was no difference in sNfL level prior to tafamidis compared to on-tafamidis (39.6 ± 6.5 vs 39.3 ± 9.2 pg/mL, respectively; p = .969). Utilizing a multivariable regression analysis, only N-terminal pro b-type natriuretic peptide (NT-proBNP) was associated with sNfL level in our overall cohort (p < .001), Figure 1.
Conclusions: In this pilot study of patients with ATTR-CM, sNfL levels were similar regardless of variant status, presence of PN symptoms, or tafamidis treatment, while elevated NT-proBNP was independently associated with increased sNfL.
Abstract
Topic: Prognosis ATTR
Background: The coupling between the right ventricle and the pulmonary artery (RV-PAc) describes the right ventricle's ability to adjust to an increased afterload. In addition to pulmonary arterial hypertension (PAH), increased afterload on the RV can result from left ventricular diastolic stiffness caused by the deposition of Transthyretin amyloid (TTR) fibrils. While RV-PAc is a validated prognostic parameter in PAH, its prognostic implication in TTR-cardiomyopathy (ATTR-CM) is unclear.
Objectives: To evaluate the prognostic impact of RV-PAc in ATTR-CM.
Methods/Results: In this multicentre study, RV-PAc was investigated by the echocardiographic surrogate of ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP) in 418 patients with ATTR-CM treated with TTR-stabilizer. The primary endpoint, all-cause mortality, occurred in 11% of patients during a mean follow-up of 605 ± 378 days. The RV-PAc ratio emerged as a robust marker for risk stratification with a determined optimal cutoff of 0.244 mm/mmHg (AUC 0.739 [95% CI 0.67–0.82]) by ROC and Youden’s J analysis. Patients with RV-PAc ratio <0.244 mm/mmHg (impaired RV-PAc, n = 55) exhibited significantly lower survival (HR 5.21, 95% CI 2.91–9.30, p < .001) than those with RV-Pac ratio ≥0.244 mm/mmHg. In multivariate analysis of echocardiographic parameters, reduced RV-PAc was a strong predictor of mortality (OR 4.16, 95% CI 2.16–8.04, p < .001).
Conclusion: Impaired adaption of the RV to increased afterload is associated with worse outcome in ATTR-CM patients. RV-Pac ratio can serve as an echocardiographic predictor for all-cause mortality, irrespective of left ventricular function. Therefore, determination of RV-PAc could improve risk stratification for ATTR-CM patients.
Abstract
Topic: Treatments of AL
Primary AL-amyloidosis is a rare disease affecting ∼10 per million per year. Comprehensive data on the disease from India is lacking. We identified 30 cases of Primary AL Amyloidosis (Median age 64 years, range 45–79, 60% males) at Tata Medical Center Kolkata, in between 2011 and 2023 and provide an account of clinical features, organ involvement, responsible light chain, treatment, and survival outcomes.
Most common presenting symptom was pedal edema (50%) followed by dyspnea on exertion (23.3%). Tongue hypertrophy was found in 13.3% cases. Renal involvement was most common (63.3%) followed by involvement of heart (46.6%), bone marrow (30%), Gastrointestinal/Liver (13.3%). 1 case each involving nerve, urinary bladder, lymph node was found. Responsible light chain was lambda in 73.3% cases. Bortezomib based triplet regimens were used as first line treatment in most of the cases (70%), followed by daratumumab based quadruplet regimens (10%), doublet regimens (10%) and non-bortezomib triplet regimen (CTD, 6.6%). Autologous stem cell transplant was done in 2 patients (6.6%).
Median Overall Survival (OS) and Event Free Survival (EFS, event: death, relapse, or progression) was 10 months and 5 months respectively. OS with and without cardiac involvement were 7 months and 30 months (p = .019), EFS for the same groups were 7 and 4 months (p = .86). Median OS and EFS in the cases treated with bortezomib based triplet regimens were 7 months and 5 months.
The current study shows OS and EFS benefit if daratumumab was used (Figure) and increases pool of data on the disease in Indian population.
Abstract
Topic: Prognosis AL
Introduction: Hemostatic abnormalities and deregulated coagulation are common complications in AL amyloidosis. The relevant risks of thromboembolic and hemorrhagic events have not been thoroughly evaluated.
Methods/Aim: We performed a retrospective analysis in 450 consecutive newly diagnosed patients with AL amyloidosis to describe clinically significant thrombotic/hemorrhagic events. Results: VTE were reported in 6% and AEEs in 5% of patients respectively during a 55-month median follow-up. Out of 26 patients with VTE events, 18 were on anti-clonal treatment (9 on IMiDs). Lower albumin, lower eGFR, higher bone marrow infiltration, soft-tissue involvement, MiD-based therapy, and prior thrombosis were associated with a higher VTE risk. A history of thrombosis was the only independent prognostic variable (HR 9.3, p = .001, 95% CI 2.3–36.6). With regards to AEE, a history of CAD, prior AEE, baseline proteinuria and higher platelet counts at diagnosis were associated with increased risk. The median time from diagnosis to VTE was 9.5 months (0.1–107) and to the AEE 14 months (0.62–114). Significant bleeding events were reported in 9% and associated mortality was 19%. Liver involvement, higher serum creatinine and higher baseline vWF:Ag levels were linked to bleeding risk. Using competing risk analysis, the cumulative probability of thrombosis /bleeding was higher during the first year following diagnosis but a stable lower risk for both events remained for the duration of follow-up.
Conclusion: The risk of thrombotic/arterial embolic events in AL amyloidosis patients is significant but the bleeding risk is also high. Multiparametric assessment is required to initiate antithrombotic or antiplatelet therapy appropriately.
Abstract
Topic: Organ Transplant
Background and aims: Domino liver transplantation (DLT) is a crucial strategy in alleviating the organ shortage, yet the potential risk of transmitting the original disease presents a challenge in effectively informing recipients.
Methods: This is a retrospective monocentric study, including adult patients who received grafts of donors with hereditary amyloid neuropathy between 1997 and 2022. The research employs Cox models to identify predictive factors for the development of neuropathy symptoms and for survival in these patients.
Results: A total of 183 patients underwent DLT, with a median follow-up of 12.4 [3.8, 20.1] years. Among them, 90 (49.2%) experienced neuropathy symptoms during a follow-up period of 11.4 [6.3, 17.8] years. Sensory loss and neuropathic pain were the prevalent symptoms, reported by 4 (2.4%) patients at 5 years post-LT, reaching 20 (14.5%) and 21 (21.2%) at 10 years. The survival rates were 84.9% at 5 years and 68.1% at 10 years. Death was attributed in 25 (20.3%) to cancer recurrence post-transplantation to amyloidosis in 5 (4.1%) cases. 125 (68.3%) donors carried the Val MET 30 mutations. The use of steroids (HR =1.53, p = .05; HR =1.66, p = .05) was a predictive factor of post LT amyloidosis symptoms. Cholangiocarcinoma as an indication for LT (HR =1.476, p = .045) and the use of Tafamidis (HR =2.59, p = .001) were identified as independent factors contributing to poor survival after LT in the multivariate analysis.
Conclusion: DLT demonstrated an equivalent survival rate compared to non-Domino liver transplantation, with survival primarily associated with the initial disease but half of the patients developed symptoms of amyloid neuropathy.
Abstract
Topic: Organ Transplant
Background and aims: Familial amyloid polyneuropathy (FAP) is an autosomal dominant multisystemic fatal disorder. Since more than 90% of TTR is produced within the liver, it is expected that liver transplantation (LT) will stop disease progression and that variant TTR will clear from the serum.
Methods: This is a retrospective monocentric study including adult patients transplanted for FAP between 1997 and 2022. The research employs Cox models to identify predictive factors for the progression of neuropathy symptoms after LT and for survival.
Results: A total of 257 ATTRv-PN patients underwent LT, with a median follow-up of 12.4 [3.8, 20.1] years. 56% of donors carried Val MET 30 mutations. Symptom outcomes post-LT revealed improvement in 3.5%, stability in 48.6%, and worsening in 47.9%. At 5 and 10 years, exacerbation of neuropathic symptoms was observed in 33.3% and 51.7%, respectively, with prevalent symptoms including sensibility loss (47.5%), neuropathic pain (38.2%), walking difficulties (39.3%), diarrhea (47.2%), and pacemaker use (42%). Survival rates were 90.6% at 5 years and 77.3% at 10 years. Univariate analysis identified age at LT (p < .001), AST and ALT at 5 years post-LT (p = .03 and 0.01), and the use of steroids (p < .001) and tacrolimus (p < .001) 1 year after LT as significant predictors of disease progression. Cox model results highlighted a notable negative association between disease's progression post-LT (HR =11.961, p = .001) and survival.
Conclusion: Despite symptom progression in half of the patients post-LT, it is associated with poor survival. Early detection and alternative treatments post-LT are crucial for improved outcomes.
Abstract
Topic: Diagnosis ATTRwt
Background: Transthyretin (TTR) amyloidosis is characterized by the misfolding, degeneration, and deposition of a liver-produced protein, primarily in cardiac muscle and peripheral nerves. This progressive deposition leads to significant morbidity and mortality for patients. Therefore, insights into early disease identification will enable faster access to disease-modifying therapies, which have been shown to improve mortality.
Objective: This project aims to characterize patients with varying ventricular septal thicknesses to assess trends. It is not known whether those with a less thick septum are indeed in an earlier stage of the disease process or if they experience fewer disease complications.
Methods: A cohort of 30 randomly selected patients from the London Health Sciences Centre (LHSC) Cardiac Amyloid Clinic, diagnosed with TTR cardiac amyloid in 2023, was chosen. Predefined characteristics at the time of the initial referral were retrospectively collected. Electronic medical records were accessed to compile data. Parameters of note include left ventricular end-systolic dimension (LVSd) size, pyrophosphate (PYP) scan heart-to-contralateral lung ratio, ejection fraction, diuretic requirement, NYHA Class, and medical history. Patients were also subdivided based on LVSd size at diagnosis (14 mm or less vs. 15 mm or greater) to observe any potential trends.
Results: This research reveals several meaningful associations. It showcases a linear relationship between LVSd size and PYP heart-to-contralateral lung ratio (p = .04) (Table 1). The results also suggest that the larger the LVSd, the greater the disease morbidity related to increasing NYHA Class and diuretic use. Lastly, it demonstrates a higher prevalence of atrial fibrillation in those with larger LVSds.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Systemic light chain amyloidosis (AL) patients often have a lag period of increasing symptoms during which they seek healthcare. We leveraged electronic health records (EHR) data from the TriNetX research network to describe the incidence, timing, and co-occurrence of 19 red-flag diagnoses among a cohort of AL patients identified between 10/2015–12/2020. These red-flag diagnoses represented AL features and were identified using ICD codes up to 36 months pre-AL diagnosis. Among 1401 U.S. patients with at least 36 months of pre-AL EHR data, 46% were females, 16% were non-Hispanic Black, and 6% were Hispanic. The median age was 71 (range, 21–91) years. Dyspnea and fatigue were the most prevalent, identified in 55% and 45% of patients at AL diagnosis at a median time of 8.1 (IQR 2.7, 15.9) and 7.8 (1.9, 15.8) months, respectively (Figure). The cumulative number of red-flag diagnoses was a median (IQR) of 2 (0–4) at -24 months, 4 (2–7) at -6 months, and 5 (2–9) at AL diagnosis. Analyses of pairwise co-occurrence of diagnoses indicated high association (Cole’s coefficient, CC >0.6), with the highest inter-organ system association between autonomic neuropathy (AN) and dyspnea (CC 0.76, p 0.009), neuropathy and purpura (CC 0.68, p < .001), AN and fatigue (CC 0.68, p 0.004), fatigue and purpura (CC0.65, p < .001), and altered bowels and AN (CC0.60, p 0.006). These findings provide novel information about the timing and co-occurrence of red-flag symptoms already discovered by healthcare providers as diagnoses in existing EHR of patients and could be used to develop algorithms for early identification of AL.
Abstract
Topic: Pathology
Be.Amycon addresses the urgent need for improved amyloidosis diagnosis and management in Belgium through a comprehensive, multi-center approach. The goal is to enhance patient outcomes by establishing a collaborative network of dedicated researchers and clinicians, tackling difficulties in diagnosis, and typing of amyloid, leading to faster diagnosis, earlier treatment intervention and new therapeutic options.
Our initiative encompasses a range of strategies aimed at transforming the current state of amyloidosis management in Belgium. One focus is the implementation of mass spectrometry for amyloid typing. By optimizing the diagnostic process, we aim to deliver more timely and precise diagnoses, offering a leap forward in patient care.
In addition to technical advancements, an educational program for healthcare providers will be initiated, in conjunction with a close collaboration with the patient advocacy in order to centralize and optimize patient care.
The initiative’s holistic vision covers the entire spectrum of amyloidosis research and care, from fostering awareness and expertise, to establishing a decentralized biobank for amyloidosis samples, to deep proteomics analysis of protein deposits. At this international amyloidosis conference, we aim to share insights into the challenges faced in Belgium while presenting the broader goals of Be.Amycon. We not only want to address immediate changes in amyloidosis care, but also meet high standards for comprehensive, collaborative efforts in the field. We aim to share our vision and progress, hoping to inspire similar approaches worldwide.
Abstract
Topic: Treatments of ATTR
Introduction: In the treatment of AL and AA amyloidosis, better outcomes are associated with lower circulating concentrations of amyloidogenic serum free light chains (Palladini, et al. J Clin Oncol. 2012) and serum amyloid A protein (Lachmann, et al. N Engl J Med. 2007). In ATTR amyloidosis, the relationship between residual serum TTR concentrations ([TTR]) and clinical outcomes has not been established. We report [TTR] following administration of investigational CRISPR-based therapy NTLA-2001 in the first-in-human trial with the aim of enabling the development of biomarker-based response criteria in ATTR amyloidosis.
Methods: In the ongoing NTLA-2001 phase 1 trial (NCT04601051), 62 subjects (ages 19–86; 9 women; 33 ATTRv-PN; 29 ATTR-CM) received weight-based (0.3, 0.7, or 1.0 mg/kg) or fixed-dose (55 or 80 mg) one-time infusions. Total circulating [TTR] was measured by immunoassay to detect total (wild-type and mutant) [TTR] at pretreatment and predetermined times post infusion. Data were collected through 730 days (0.3 mg/kg cohort).
Results: Median (interquartile range [IQR]) absolute [TTR] measured at baseline was 213.2 ug/mL (158.0–268.8). Median (IQR) percent reduction from baseline for [TTR] on Day 28 was 91.4% (88.2–94.2%) among all 62 subjects. Median (IQR) absolute [TTR] measured on Day 28 was 16.9 ug/mL (10.8–23.6) and remained stable thereafter. Median (IQR) maximum [TTR] change from Day 28 onward was −1.4 ug/mL (−4.7–1.7). NTLA-2001 was generally well tolerated; most adverse events were mild in severity.
Conclusions: The consistently low and stable absolute [TTR] levels achieved with NTLA-2001 could facilitate development of biomarker-based response criteria in ATTR amyloidosis, analogous to those in other systemic amyloidosis.
Abstract
Topic: Treatments of ATTR
Background: ATTR amyloidosis is a progressive condition most commonly presenting as cardiomyopathy and/or polyneuropathy. Current disease-modifying treatments require repeat administration, presenting a significant burden and leaving patients at risk for disease progression/death. NTLA-2001, an investigational, in vivo, CRISPR-based, one-time gene editing therapy, has been administered to 72 participants in an ongoing phase 1 study (NCT04601051) with interim data demonstrating a favorable safety profile, with rapid, consistent, and durable reductions of serum transthyretin to low levels following a single intravenous infusion ≥0.3 mg/kg.
Methods: MAGNITUDE (NCT06128629) is a phase 3, multinational, multicenter, randomized, double-blind, placebo-controlled study evaluating NTLA-2001 in approximately 765 patients with ATTR-CM. Eligible patients are ages 18–90 with mutant or wild-type ATTR-CM, NYHA class I-III, NT-proBNP ≥1000 pg/mL (≥2000 pg/mL for participants with atrial fibrillation), and symptoms of heart failure optimally managed and clinically stable ≤28 days of administration of study drug. Stratification is by NAC stage, TTR genotype (mutant vs wild-type), and concomitant tafamidis use. Patients will be randomized 2:1 to a single 55-mg intravenous infusion of NTLA-2001 or placebo. The primary endpoint is a composite of CVrelated mortality and frequency and timing of CV events; secondary endpoints are change from baseline to 18-month serum TTR and KCCQ-OS score. Exploratory endpoints include change in 6-min walk distance, NT-proBNP, and ATTR-Quality of Life score. Patients will undergo serial echocardiography and CMR imaging (select sites). Safety will be evaluated throughout. Minimum follow-up is 18 months, with the majority estimated to have ≥30 months follow-up at time of primary analysis.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
The effectiveness of therapeutic strategies for hereditary amyloidosis depends on the specific protein involved, therefore, it is crucial to accurately determine its nature. Moreover, following the diagnosis, the search for the mutation within relatives allows the clinical advice or the possibility of counting on a healthy relative who could be a donor in the case of organ transplantation. Here we report for the first time in Argentina the precise diagnosis of hereditary amyloidosis by whole exome sequencing and GATK calling pipeline, identifying a variant of fibrinogen Aα chain in a patient. Our finding has opened the possibility of curative transplantation. Bioinformatics strategies were applied to suggest potential explanations of the fibrinogen variants pathogenicity. In silico structural analysis suggests that the variantś pathogenicity may be attributed to a heightened susceptibility to yield a peptide prone to deposit as an oligomer with a β-sheet structure. We conclude that exploiting the comprehensive coverage of whole genome sequencing will help fill a vacant stage in the diagnosis of hereditary amyloidosis in Argentina, enabling a faster and more accurate treatment of underserved patients.
Copyright for this individual abstract is: © 2024 CONICET (Natl. Council of Scientific and Tech. Research Argentina). Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Pathology
Background: Patients with two different amyloid types have rarely been previously described. It is critical to identify all types of amyloids in a patient as amyloid therapies vary dramatically depending on the specific precursor protein.
Design: We queried our reference laboratory database of amyloid specimens from all anatomic sites typed by mass spectrometry-based proteomics (LC-MS/MS) for patients with diagnoses of two different types of amyloids. Demographic data including patient age, sex, and anatomic site of involvement was collected. The mass spectrometry proteomic features were reviewed.
Results: We identified 65 patients with two amyloid types (48 males (74%), 17 females (26%)). The average age at initial diagnosis was 74 years (range 26 to 91 years). 27 patients (42%) had cardiac involvement. The two types of amyloids were present either in two different anatomic locations (17 patients, 26%), in different anatomic compartments within a single specimen (33 patients, 51%), or in the same anatomic compartment within a single specimen (15 patients, 23%). shows the various combinations we identified. The most common combination was AL plus ATTR (38 patients, 58%), which occurred in 19 patients with cardiac involvement.
Table 1. Dual amyloid diagnoses.
Conclusion: The findings highlight the importance of determining the amyloid type in all cases, including careful review of the biopsy material to evaluate for distinct areas with different distribution, and considering the possibility of a second amyloid type when the clinical findings are not explained by the initial amyloid type. In some patients, this may require biopsy from a second anatomic site.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
The extracellular matrix (ECM) is a complex tridimensional scaffold that actively participates in physiological and pathological events. The objective of this study was to test whether structural proteins of the ECM and glycosaminoglycans (GAGs) may favor the retention of human apolipoprotein A-I (apoA-I) variants associated with amyloidosis and atherosclerosis. Biopolymeric matrices containing collagen type I (Col, a main macromolecular component of the ECM) with or without heparin (Hep, a model of GAGs) were constructed and characterized, and used to compare the binding of apoA-I having the native sequence (Wt) or Arg173Pro, a natural variant inducing cardiac amyloidosis. Protein binding was observed by fluorescence microscopy and unbound proteins quantified by a colorimetric assay.
We observed that both, Wt and Arg173Pro bound to the scaffolds containing Col, but the presence of Hep diminished the binding efficiency. Col-Hep matrices retained Arg173Pro more than the Wt. The retained protein was only partially removed from the matrices with saline solutions, indicating that electrostatic interactions may occur but are not the main driving force. Using in addition thermodynamic molecular simulations and size exclusion chromatography approaches, we suggest that the binding of apoA-I variants to the biopolymeric matrices is driven by many low affinity interactions.
We conclude that under this scenario Col-Hep scaffolds contribute to the binding of Arg173Pro, as a cooperative platform which could modify the native protein conformation affecting protein folding. We show that the composition of the ECM may be key to the protein retention before the deposition as amyloid fibers.
Copyright for this individual abstract is: © 2024 CONICET (Natl. Council of Scientific and Tech. Research Argentina). Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Prognosis AL
Background: Complete eradication of the plasma cell clone is key for the treatment of AL amyloidosis; undetectable minimal residual disease (MRD) is likely to improve outcomes further. Aim: To evaluate the prognostic impact of BM assessed MRD in patients with AL amyloidosis. Methods: We used next generation flow cytometry (NGF) to detect MRD (sensitivity of 2.3 × 10−6) in 126 patients, in hemVGPR/hemCR, ≥6 months after treatment initiation.
Results: In 46 patients (37%) MRD was undetectable. Median time from start of therapy to MRD testing was 9.1 months (3.22–69.6). Baseline characteristics were similar for MRDneg and MRDpos groups; no factors were identified that could predict undetectable MRD. More patients in the MRDneg group had CR (77% vs 49% of MRDpos, p = .003). There was no association between MRD status and dFLC <10 or iFLC <20 at best response. Organ responses were comparable among the two groups (p > .05), seen in 66% of patients. Median follow-up after MRD was 30.9 months (0.3–91.6 months); 19 patients started subsequent treatment [n = 2 (5%) MRDneg vs n = 17 (23%) MRDpos, p = .015]. Median time to subsequent treatment after MRD positivity assessment was 22.3 months (6.83–42.81). Overall, 18 patients have died, 4 among MRDneg and 14 among MRDpos patients. 2-year EFS (hemProgression, second line initiation or death) was 93% vs 76% for MRDneg vs MRDpos patients (p = .09), which was more pronounced among those with hemVGPR (100% vs 76%); however, there was no statistically significant OS difference.
Conclusion: Achieving MRD-negativity has implications with regards to long-term outcomes, such as hematologic relapse, need for subsequent therapy and survival.
Abstract
Topic: Diagnosis ATTRwt
Symptomatic carpal tunnel syndrome (CTS) and lumbar stenosis (LS) seem to precede the cardiac manifestations of cardiac amyloidosis (CA) due to transthyretin amyloidosis (ATTR), so they could represent early markers of CA. Our purpose is to evaluate the prevalence of amyloidosis in patients undergoing CTS or LS surgery, in an endemic area of the TTR mutation Val50Met (ATTRv).
237 operated patients have been included (183-CTS,54-LS) in whom an intraoperative biopsy was obtained for histopathological analysis using Congo Red staining for amyloid detection and immunohistochemistry(IHC) or mass spectrometry (MS) for subtyping in amyloid A (AA), kappa, lambda and ATTR.A blood and urine test to rule out a monoclonal component and a cardiac scintigraphy (CS) with 99mTc-DPD to detect myocardial uptake were performed, which analysis was visual by Perugini scale and semiquantitative by heart-to-contralateral-lung ratio (H/CL).A cardiac SPECT/CT was performed in cases with a positive CS.
Total of 204 biopsies were obtained (154-CTS,50-LS),16 of them were amyloid positive (8-CTS,8-LS).203 laboratory tests and CS have been performed:5/203 CS were positive (grade 2–3) in 4 patients who underwent CTS surgery (2 with positive biopsies for amyloid and 2 without biopsy) and 1-LS with also positive biopsy. In 15/203 laboratory tests, a monoclonal component was detected. Positivity for amyloid has been obtained in 18/237 cases (7.6%):16 positive biopsies (2 of them with positive blood/urine test and 3 of them with positive CS) and 2 positive CS without biopsy.
In the follow-up (2.41 years) of patients with positivity,27.8% (5/18) manifests cardiomyopathy,4 of them with positive CS, and 88.9%16/18) has previously other orthopedic manifestations.
The estimated prevalence of amyloidosis in our series of surgically treated patients with CTS or LS is 7.6%
Abstract
Topic: Prognosis AL
Background: We previously published a CA-AI-ECG model to aid in the diagnosis of cardiac amyloidosis (CA). The current study aims to determine if CA-AI-ECG predicts death and/or development of subsequent CA among MM patients undergoing ASCT.
Methods: MM patients receiving ASCT at Mayo Clinic from 7/1/2000–1/1/2023 were included in this retrospective study if they had: consented to research; no diagnosis of amyloidosis at ASCT; a Mayo ECG within 365 days of ASCT. Patients’ ASCTs were categorized as early (ASCT <1-year-after-diagnosis) or delayed ASCT (ASCT >1-year-after-diagnosis). Outcomes were evaluated in the context of ECG’s meeting the threshold to CA using the CA-AI-ECG algorithm (CA-AI-ECG+).
Results: 2934 patients were included: 2367 early ASCT; and 567 delayed ASCT. 159 patients were CA-AI-ECG+: 5.6% and 4.8% in early and delayed ASCT groups, respectively. Death within 100 days of ASCT was not higher among CA-AI-ECG + patients. Twenty-five patients (0.9%) were diagnosed with AL amyloidosis at median of 38.2 months after ASCT and had a 3-fold higher rate of CA-AI-ECG + pre-ASCT (p = .043).
Overall survival was marginally worse for the CA-AI-ECG + population (Figure) and most pronounced in the delayed ASCT population. In the delayed ASCT group, inferior survival associated with pre-ASCT CA-AI-ECG + was independent of age, ISS, R-ISS.
Conclusions: In a population of MM patients at an amyloidosis center, the finding of a CA-AI-ECG + occurred in approximately 5% of patients and was associated with inferior overall survival. Further study to dissect the mechanisms of our findings and to validate them at other centers is of interest.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
This project’s target audience is health professionals (HP), health scientists (HS), health sciences students (HSS), and the public in West Africa, where the prevalence of the TTR V112I is 2.5%, with activities timeframe May 2022 to June 2024 in Ghana and expansion to Burkina Faso, Guinea, Ivory Coast, Nigeria, and Sierra Leone from March 2024 to February 2026.
A pre-awareness survey in Ghana yielded 2180 respondents of 1336 HP, 40 HS, 692 HSS, and 112 grouped under others, of which only 262 HPs, 16 HS, 97 HSS, and 11 others have heard of Transthyretin Amyloidosis before project activities on social media and national television/radio broadcasts. Also, in-person and eLearning training activities for HP/HS/HSS revealed pre-training test and post-training test activities among HP/HS/HSS groups yielded a total enrollment of 1481, of which 457 out of 1061 that took the pre-training test scored 50% and above while 460 of out of the 1061 participants completed the assessment by taking the post-training test and scored 50% and above, with 1 scoring 50% and the remaining 459 scoring 70% or more. Furthermore, the modular contents have been developed for laypersons, HP/HS/HSS, and efforts to publish the awareness module in journals and support for TTR genetic testing are underway. The Transthyretin Amyloidosis Support Network (TASN) in Ghana and the Transthyretin Amyloidosis Workforce Network (TAWN) in countries under the project expansion have been established.
The overall project progression is 78.9%. We anticipate the project activities will foster collaboration to establish a West African Amyloidosis Center (WAAC).
Copyright for this individual abstract is:© 2024 C.K. Tedam University of Technology and Applied Sciences. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access varticle distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Basic Science AL
Light chain amyloidosis (AL) shares with Multiple Myeloma (MM) the overproduction of a light chain (LC), yet the resulting phenotypes differ, indicating distinct LC involvement. Previously, we performed a comparative analysis of lambda light chains from AL and MM patients, pinpointing proteolysis susceptibility under native conditions as the most distinguishing biophysical parameter. Weber et al. demonstrated in a mouse-derived gamma-LC that even a single amino acid variation in the linker between constant and variable domains leads to heightened conformational dynamics, increased proteolysis susceptibility, and elevated in vitro aggregation propensity. In this study, we aim to delineate a conformational signature that discriminates AL from MM LCs. By subjecting four AL and two MM LCs to in vitro analysis under native conditions using small-angle X-ray scattering (SAXS), we observed that the AL LCs displayed a slightly larger radius of gyration and greater deviation from the experimentally determined structure, indicating enhanced conformational dynamics. Integrating SAXS with molecular dynamics (MD) simulations to generate a conformational ensemble revealed that LCs can adopt multiple states, with variable and constant domains either bent or straight. Specifically, AL LCs favored a distinctive state where both domains had a straight conformation, maximizing solvent accessibility at their relative interfaces. This unique conformation was validated experimentally through hydrogen-deuterium exchange mass spectrometry. Such findings reconcile disparate experimental observations and offer a precise structural target for drug design investigations. Collectively, this study sheds light on the intricate conformational landscape of LCs in AL and provides insights into potential drug design interventions.
Abstract
Topic: Basic Science AL
Background: AL amyloidosis is a serious systemic disease characterized by the deposition of aggregates of immunoglobulin light chains (LCs) in the form of amyloid fibrils. The organs most often affected are the heart and kidney. Cardiac involvement determines prognosis.
Aim: Our objective was to study the cytotoxic impact of amyloid free LCs in a human cell disease model mimicking AL cardiac amyloidosis (AL-CA).
Methods: Cardiac spheroids were obtained by admixing 15% fibroblasts and 85% human inducible pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) with amyloid free LCs purified from patients’ urine to obtain a homogeneous distribution of LCs within spheroids. Spheroids were further incubated with LCs during one week before analysis. Contractility and calcium transients were analyzed by video microscopy. Cell structure was analyzed by immunolocalization on spheroid frozen sections and Western blotting.
Results: We show that treatment of spheroids with LCs induced in hiPSC-CM: (1) a disturbance in contractility and calcium transient; (2) a decrease in cardiac troponin T protein; (3) an aggregation of SERCA-2a protein.
Conclusion: We have set up a human cellular model of AL-CA, in the form of cardiac spheroids, to study the cytotoxic effects of amyloid proteins. The model enabled us to demonstrate an alteration of calcium transients which could relate to impaired contractility in the presence of LCs. The changes in SERCA-2a and cardiac troponin T proteins further indicated a disturbance of the contractile machinery by means of structural disorganization of cardiomyocytes.
Abstract
Topic: Treatments of ATTR
Background: Data are limited for patisiran in patients with hereditary transthyretin (ATTRv; v for variant) amyloidosis and comorbid chronic kidney disease (CKD). As treatments emerge for ATTRv amyloidosis, patients live longer, likely increasing the population with comorbid CKD.
Methods: Data from patisiran Phase (Ph)2 open-label extension (OLE), Ph3 APOLLO, Global OLE, and Ph3b post-orthotopic liver transplant (OLT) studies of patients with ATTRv amyloidosis with polyneuropathy were evaluated post-hoc. This analysis assessed estimated glomerular filtration rates (eGFR) and transthyretin (TTR) levels in patients with baseline eGFR <60/≥60 mL/min/1.73 m2, eGFR by baseline longitudinal strain (<–15%/≥–15%), and safety.
Results: In Ph2 OLE/APOLLO/Global OLE, 22/252 patients (8.7%) had baseline eGFR <60 mL/min/1.73 m2. During long-term patisiran treatment, mean eGFR remained relatively stable irrespective of baseline eGFR (<60/≥60 mL/min/1.73 m2) (Figure). In the post-OLT study, mean eGFR remained stable until end of study in patients with baseline eGFR <60/≥60 mL/min/1.73 m2. Patisiran treatment resulted in rapid TTR knockdown that was comparable irrespective of baseline eGFR <60/≥60 mL/min/1.73 m2 and maintained throughout the studies. Mean eGFR remained relatively stable in patients with baseline longitudinal strain <–15%/≥–15%. Patisiran had an acceptable safety profile in patients with baseline eGFR <60 mL/min/1.73 m2 with no new concerns.
Conclusion: During long-term patisiran treatment, eGFR remained relatively stable in patients with ATTRv amyloidosis with polyneuropathy and impaired kidney function (baseline eGFR <60 mL/min/1.73 m2), irrespective of baseline cardiac function (longitudinal strain <–15%/≥–15%). TTR knockdown was comparable irrespective of baseline eGFR. No new safety concerns were identified.
Abstract
Topic: Diagnosis ATTRv
Background: The study aims to validate MALDI-TOF for early A-ATTRv diagnosis using plasma samples, addressing the challenge of distinguishing carriers from healthy individuals.
Methods: Human plasma samples from Son Llàtzer University Hospital underwent C18 reversed-phase extraction using ZipTips for sample preparation. Samples were diluted 1:10 in 50 mM ammonium bicarbonate and digested with trypsin. Digested and non-digested samples were analysed by MALDI-TOF. Pre-processed spectra that passed the quality control and predictor filtering were used to develop and assess thirty predictive models. The five providing the best performance were selected: SVM, Partial Least Squares, Sparse LDA, Shrinkage Discriminant Analysis, and High Dimensional Discriminant Analysis. A 10-fold cross-validation re-sampling scheme was used for model performance assessment, statistical validation and model parameters tuning, preventing inclusion of patient replicates in the training and testing set of any fold. A majority-voting scheme applied to patient replicates classification assigns the predicted patient class. The performance of the models for digested and non-digested samples was evaluated and compared.
Results: Digested samples outperformed non-digested ones, showing 86% average accuracy when classifying healthy individuals versus carriers and 69% average accuracy predicting patients against carriers. Notably, non-digested samples posed challenges (average accuracy: 54%) in distinguishing carriers from healthy individuals.
Conclusion: The study reveals the significance of sample preparation methods, with digested samples showing improved prediction accuracy. Treatment-related proteomic changes potentially contributed to lower accuracy in discriminating carriers from patients in digested samples. Future analyses should explore correlations between treatment modalities and proteomic profiles, refini’g MALDI-TOF's applicability for ATTRv disease diagnosis.
Abstract
Topic: Treatments of ATTR
Introduction: Eplontersen improved neuropathy impairment and quality of life (QoL) versus historical placebo (placebo) in patients with hereditary transthyretin amyloidosis with polyneuropathy in the NEURO-TTRansform trial. Whether these benefits were observed in patients with worsening nutritional status (modified body mass index [mBMI]) is unknown and is the subject of this secondary analysis.
Methods: Patients from NEURO-TTRansform were categorized by treatment, by change from baseline in mBMI at Week 66 (>10% decrease; <2.5 to 10% decrease; −2.5 to +2.5% change; >2.5 to 10%; >10% increase). Change in modified Neuropathy Impairment Score +7 (mNIS +7, composite score), and Norfolk QoL-Diabetic Neuropathy (Norfolk QoL-DN) total score was evaluated.
Results: Patients (eplontersen n = 144; placebo n = 60) were of mean (SD) age, 54.9 (15.0) years, 69% were male. Overall distribution of mBMI trended towards improvement for eplontersen and worsening for placebo. Across mBMI categories, eplontersen demonstrated consistent benefit on neuropathy impairment and QoL versus placebo (Figure). Mean (95% CI) differences (Week 66) in mNIS +7 scores for eplontersen versus placebo were −29.5 ([−45.5, −13.5]; mBMI >10% decrease), −17.8 ([−30.1, −5.5]; <2.5 to 10% decrease), −17.1 ([−30.8, −3.4]; −2.5 to +2.5% change), and −8.8 ([−22.9, 5.3]; >2.5 to 10% increase). For Norfolk-QoL-DN; −24.3 ([−38.4, −10.2]; mBMI >10% decrease), −14.9 ([−29.1, −0.8]; <2.5 to 10% decrease), −15.6 ([−30.8, −0.5]; −2.5 to +2.5 % change), and −2.1 ([−13.5, 9.2]; >2.5 to 10% increase).
Conclusions: Benefits in neuropathy impairment and QoL were observed with eplontersen versus placebo, regardless of degree of mBMI change from baseline, including in patients with worsening nutritional status.
Copyright for this individual abstract is: © 2024 European Union. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Abstract
Topic: Pathology
Background: Amyloid has been shown in resected stenotic aortic (AS) valves in several studies.
We have noticed amyloid in over 75% of AS valves in our clinical routine practice. However, the nature of this amyloid has not been completely elucidated.
Objective: To better understand the nature of amyloid aggregates in resected AS valves.
Methods: We have examined 110 non-selected, deidentified valves resected due to AS. Of these, 106 had visible calcifications. Scrapings from all valves were smeared on microscopical slides and examined. The amount of amyloid was assessed (0–4+). Extract from each valve was analyzed by western blot using a rabbit antiserum against transthyretin (TTR) 50-127.
Results: Variable amounts of amyloid deposits were seen on slides from 98 of the 110 valves.
Transthyretin was present in 104 of the valve extracts. The TTR was of full length (type B) in 102 cases. TTR of fragmented type (type A) was seen in only two cases. These had moderate to large amount amyloid on the Congo-stained slides (2+ and 3+). No TTR was shown in the cases that lacked visible calcifications.
Discussion: This series shows the very prevalent presence of TTR in calcified aortic valves. Surprisingly, the TTR was of type B in all but two cases, which were of type A. This is in contrast to TTR in systemic ATTRwt amyloidosis which is always of type A. Our findings may indicate that presence of ATTR amyloid in calcified aortic valves more rarely is a sign of systemic amyloidosis.
Abstract
Topic: Treatments of ATTR
Background: Recent evidence has shown that many patients with ATTR amyloidosis develop a mixed phenotype of both polyneuropathy and cardiomyopathy, with polyneuropathy and musculoskeletal symptoms manifesting first, well before a confirmed diagnosis of cardiomyopathy. The objective of this study was to evaluate the occurrence of polyneuropathy and musculoskeletal manifestations prior to a confirmed diagnosis of ATTR amyloidosis with cardiomyopathy (ATTR-CM) in patients enrolled in APOLLO-B (NCT03997383).
Methods: Baseline disease characteristics and medical history, coded using Medical Dictionary for Regulatory Activities (MedDRA version 23.0), collected during the screening period from APOLLO-B were analyzed in the overall study population and in patients by ATTR amyloidosis type (hATTR, wtATTR) across both treatment arms. The event prevalence and time from event onset to diagnosis of ATTR amyloidosis with cardiomyopathy were summarized descriptively. Additional analyses of polyneuropathy and musculoskeletal manifestations in a matched cohort of patients, as a comparator group, are ongoing.
Results: Overall, medical histories of 359 ATTR-CM patients were analyzed, of which there were 72 hATTR and 287 wtATTR patients. Polyneuropathy and musculoskeletal manifestations were found in >20% and >60% of all patients, respectively, with these extra-cardiac events occurring at least 3 years prior to a confirmed diagnosis of ATTR-CM.
Conclusion: This analysis demonstrates that polyneuropathy and musculoskeletal manifestations may be early signs that are potentially overlooked in patients with ATTR-CM. Multisystem clinical assessment and early identification of non-cardiac manifestations are therefore crucial for management of this debilitating condition.
Abstract
Topic: Diagnosis AL
Typical presentation of renal AL-amyloidosis consists of massive albuminuria resulting in nephrotic syndrome. However, renal Al may sometimes feature predominant vascular deposition and present with lower degree of proteinuria.
We retrospectively collected data for 35 French patients with kidney biopsy-proven AL-amyloidosis and proteinuria/creatinuria ratio <1 g/g at diagnosis. At diagnosis, median proteinuria was 0.58 g/g (0.37–1) with median serum creatinine level of 167 (127–213) µmol/L and median eGFR of 36.2 (24.3–49.6) mL/min/1,73 m2 (CKD-EPI equation). Cardiac involvement was present in 67% of cases (stage 3 in 61%). Hypertension was present in 51% of patients at diagnosis.
Monoclonal gammopathy was detected in 94% of patients. Hematological diagnosis was MGCS (n = 24, 69%), symptomatic multiple myeloma (n = 8, 23%), and Waldenström’s macroglobulinemia (n = 3, 9%). Central review of kidney biopsies revealed predominant vascular amyloid deposits in all cases (kappa n = 12, lambda n = 23). Nine percent of patients displayed severe (>50%) interstitial fibrosis. Proteomic analysis of kidney biopsies from 5 patients with lambda LC deposits revealed an overrepresentation of the VLambda 6–57 variability subgroup.
First-line treatment consisted of dexamethasone, alkylating agent and bortezomib triplet regimen (n = 14, 50%), melphalan-dexamethasone doublet (n = 8) or rituximab-bendamustine for IgM clones. The hematological response rate was 43%, with CR-VGPR rates of 38%. Renal response occurred in 17% of patients. Median overall survival was 82 months (178 months if VGPR/CR vs 16 months if NR/PR (p = .002)). Renal median survival was 56 months.
In conclusion, low-grade proteinuria vascular renal AL-amyloidosis is associated with severe initial presentation and poor outcomes.
Abstract
Topic: Diagnosis AL
Background: Carpal tunnel syndrome (CST) is an early manifestation of systemic amyloidosis. We conducted a prospective analysis with an aim of determining the incidence of AL amyloidosis in patients with CST and monoclonal immunoglobulin (mIg).
Methods: In a two-year period, patients referred to the plastic surgery outpatient clinic or neurophysiology unit were invited to participate in the study. Serum and urine protein electrophoresis with a free light chain (FLC) assay were analyzed, together with parameters of organ failure. Patients with proven mIg were invited to proceed with a biopsy of ligamentum transversum in the case of surgical release or an abdominal fat biopsy in the case of conservative management of CST.
Results: 94 patients with CST participated in the study. mIg was found in 8 patients (9 %), half of them agreed with further diagnostics. One patients IgG lambda disappeared on first follow up and due to lack of symptoms we did not proceed with biopsy. Second patients with IgG lambda, CST, polyneuropathy and increased NT-proBNP underwent abdominal fat biopsy without evidence of amyloid deposition. The abdominal fat biopsy of a third patient with IgM kappa and axonal polyneuropathy was negative for amyloid deposition and on further follow ups, the PNP was contributed to inherited CMT2 neuropathy. Fo’rth patient's biopsy of ligamentum transversum revealed ATTR with coincidental mIg IgG kappa.
Conclusion: In this prospective analysis, 9% of patients with CST had mIg. No evidence of AL amyloidosis was found on histological specimens. One patient was diagnosed with early stage wtATTR.
Abstract
Topic: Basic Science AL
Background: Systemic amyloid deposits are characteristically acellular with no surrounding inflammatory reaction. We initially speculated that the lack of immune infiltrate into amyloid deposits results from immunologic indifference towards amyloid. However, recent studies have revealed that a subset of AL patient derived amyloid material is readily recognized and engulfed by macrophages (PMID:36541892). Even so, tissue sections from these patients indicated that amyloid deposits are immunologically acellular in areas of heavy amyloid deposition. We hypothesized that amyloid toxicity could induce an immunologic acellular environment in vivo. In vitro studies have indicated that purified amyloidogenic light chains induce cardiomyocyte toxicity, but analysis of human amyloid extract material, has not been similarly evaluated.
Methods: Using human-derived amyloid extract from AL patients, we assayed amyloid uptake and the correlation between uptake and cell death by flow cytometry using human macrophage, hepatocyte, and cardiomyocyte cell lines.
Results: Cell death, of all cells analyzed, coincided with amyloid uptake and this relationship had a positive correlation. Additional studies in macrophages analyzing amyloid binding versus amyloid uptake indicated that amyloid binding to macrophages does not induce cell death, rather toxicity is induced upon engulfment of amyloid material. We next sought to opsonize amyloid material to assess the impact of FcR mediated phagocytosis on toxicity. Amyloid opsonization protected macrophages from amyloid-induced death in a dose dependent manner.
Conclusion: These results indicate that uptake of amyloid through non-FcR mediated phagocytosis by macrophages induces cellular toxicity, but opsonization can circumvent amyloid induced toxicity, underscoring the importance of opsonic amyloid-reactive therapeutics.
Abstract
Topic: Treatments of ATTR
ATTR amyloidosis is a progressive, debilitating disease resulting from accumulation of toxic TTR fibrils leading to multi-system tissue injury. We evaluated the efficacy and safety of RNAi therapeutics (patisiran and vutrisiran) across pivotal and real-world studies.
RNAi therapeutics have been studied for 10 years across trials with patients representing a broad spectrum of disease etiology, manifestations, and burden (816 patients and 2299 patient-years of treatment; Figure).
Patients treated with RNAi therapeutics demonstrated rapid serum TTR knockdown (>85% reduction) with indication of effect on cardiac and neurologic biomarkers (NT-proBNP, troponin I/T, NfL) at 3–6 months. Beneficial effect on cardiac structure and function (nominal significance in LV mass, stroke volume, GLS at 12 m in APOLLO-B; LV wall-thickness, GLS, cardiac output, LVEDV at 18 m in APOLLO; cardiac output, LVEDV at 18 m in HELIOS-A) and 99mTC uptake was observed. Statistically significant benefits vs placebo in clinical status (mNIS +7 –33.99 pts, mBMI 115.7, 10-MWT 0.31 m/s at 18 m in APOLLO; mNIS +7 –28.55 pts, mBMI 140.7, 10-MWT 0.239 m/s at 18 m in HELIOS-A; 6-MWT 14.69 pts in APOLLO-B at 12 m) and QoL (Norfolk-QOL –21.1 pts, RODS 9.0 pts, EQ-VAS 9.5 pts at 18 m in APOLLO; Norfolk-QOL –21.1 pts, RODS 8.4 pts, EQ-VAS 13.7 pts at 18 m in HELIOS-A; KCCQ 3.7 pts at 12 m in APOLLO-B) were observed at 6–9 months.
Across studies, RNAi therapeutics were well tolerated; most AEs were mild or moderate in severity and consistent with those expected in ATTR amyloidosis.
Patients representing a diverse ATTR population treated with RNAi therapeutics in long-term clinical and real-world studies demonstrate favorable efficacy and safety.
Abstract
Topic: Treatments of AL
The ongoing, prospective, phase 2 EMN27 (NCT04617925) study assesses the efficacy and safety of belantamab mafodotin (belamaf) monotherapy in patients with relapsed/refractory light-chain amyloidosis (RRAL). The study enrolled adult patients with RRAL, adequate organ function, and Mayo2004/European cardiac stage ≤ IIIA. Belamaf 2.5 mg/kg (or 1.92 mg/kg for toxicity) is administered Q6W for ≤8 cycles. Herein, we present updated study results (cutoff date: 15/12/2023).
The enrollment of the 35 patients is completed and all patients are included in this analysis. Of these, 5 (14.3%) continue treatment, 26 (74.3%) discontinued, and 4 (11.4%) completed treatment. The median number of belamaf administrations was 3.0 (1.0–8.0). At a median (range) follow-up of 12.7 months (3.2–25.9), the overall hematologic response (≥partial response) and ≥ very good partial response rates were 51.4% (18 patients) and 31.4% (11 patients); the respective rates for patients previously treated with daratumumab (n = 26 [74.3%]) were 50% (13 patients) and 34.6% (9 patients). Median duration of hematologic response (time from first response to hematologic progression or treatment/disease-related death) was not reached. All patients experienced >1 adverse event (AE) related to study treatment; ocular toxicity was the most common. Three (8.6%) patients had a non-belamaf-related fatal AE.
Belamaf monotherapy is active in heavily pretreated patients with RRAL without unexpected toxicity. Belamaf could be a valid treatment option for this difficult-to-treat patient population. Conceivably, combinations of belamaf with standard-of-care systemic treatments could allow for longer belamaf dosing intervals (Q8W/Q12W), which may reduce ocular toxicity while maintaining or improving efficacy.
Table. Baseline characteristics and efficacy/safety outcomes in patients with relapsed/refractory AL amyloidosis treated with belantamab mafodotin monotherapy.
Abstract
Topic: Treatments of AL
EMN22 (NCT04131309), an ongoing, prospective, phase 2 study, primarily assesses the 6-month overall survival (OS) of patients with newly diagnosed AL amyloidosis (NDAL) and Mayo2004/European stage 3B, who are treated with daratumumab monotherapy. Daratumumab is administered at the standard dose and schedule (initially IV and since 02/2020 as SC) for a maximum of 2 years. Patients not achieving ≥ hematological very good partial response by C4 can additionally receive bortezomib and dexamethasone (Vd). The planned accrual of 40 patients has been completed, and herein, we present updated study results (cutoff date 15/12/2023) ().
Table 1 Baseline characteristics and efficacy/safety outcomes in patients with newly diagnosed AL amyloidosis treated with daratumumab monotherapy.
Four (10.0%) patients continue treatment, 26 (65.0%) discontinued, and 10 (25.0%) have completed the 2-year treatment. At a median (range) follow-up of 10.3 months (<0.1–50.1), the median number of daratumumab administrations was 18.0 (1.0–36.0). Ten (25.0%) patients received Vd. The 6-month OS rate (primary endpoint) was 65.0% (95% CI: 48.2–77.6); median OS was 10.3 (95% CI: 4.1–32.1) months. At 6 months, 31 (77.5%) patients have achieved hematologic response (50% hemVGPR or better), 13 (32.5%) any organ response, and 11 (27.5%) cardiac response. Overall cardiac response was 50% (10% carCR, 30% carVGPR and 10% carPR). All patients experienced ≥1 serious (SAE) or non-serious adverse event, and 17 (42.5%) had a fatal SAE, without new toxicity signals.
In patients with stage 3B NDAL, daratumumab monotherapy induced deep hematologic responses with a 6-month OS of 65.0%. No new safety signals were observed. Based on these outcomes, daratumumab monotherapy may be considered as a major treatment option for these patients.
Abstract
Topic: Treatments of AL
In light chain (AL) amyloidosis, current plasma cell targeting therapies can only control the production of new light chain proteins. However, the demand for therapies that restore organ function by targeting existing amyloid deposits for removal remains unfulfilled. Current anti-light chain fibril antibodies have not led to desired clinical outcomes, partly due to the challenge of patient-to-patient light chain sequence variability. We bring a novel approach to target misfolded light chains, with a proven track record of success that sets us apart from previous efforts. We use a validated, structure-guided target discovery platform based on the foundational science that we previously used to help discover misTTR (PRX004/NNC6019), a misfolding-specific antibody that has demonstrated positive cardiac response in phase I trials in patients with ATTR cardiomyopathy. Using this approach, we have identified potent and specific antibodies towards a universal and highly accessible target on all misfolded light chains. These antibodies are conformation-specific and selectively bind misfolded and amyloid forms of multiple light chain variants without binding to their native conformations. These antibodies also successfully capture amyloid pathology in patient biopsy tissues without cross-reactivity to control tissue and induce phagocytic uptake of light chain amyloid in cell-based and small animal models. These antibodies serve as development candidates for an amyloid-clearing therapy in patients with AL amyloidosis.
Copyright for this individual abstract is: © 2024 Paradox Immunotherapeutics Inc. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Basic Science AL
Background: Amyloid-specific antibodies have been shown to opsonize and enhance amyloid clearance in mouse models. However, the complex immunological mechanisms by which amyloid is removed have not been clearly defined. Previous reports from preclinical in vivo studies suggest polymorphonuclear cells (i.e. neutrophils) can affect amyloid removal. Therefore, we sought to analyze how neutrophils contribute to amyloid clearance, using a murine amyloidoma model.
Methods: Mouse models in which patient-derived AL amyloid extract was implanted subcutaneously in immunocompromised mice (generating a localized ‘amyloidoma’) were used. Neutrophil recruitment to the amyloid masses, immune activation, and propensity to engulf amyloid were assessed.
Results: We identified two AL amyloid extracts, ALλ (CLA) which is refractory to clearance, and ALκ (TAL) which is readily cleared in mice. Immunophenotyping of amyloidomas from animals implanted with 2 mg either ALλ or ALκ revealed more neutrophils recruited to the ALkamyloid mass as compared to the ALλ material, which was mostly devoid of neutrophils. In vitro analyses indicated human neutrophils do not phagocytose amyloid directly. However, histological evaluation of the ALk amyloidomas revealed the presence of neutrophil extracellular traps, which were absent in ALλ amyloidomas. Using neutrophil depletion experiments in the mice, we determined that mice devoid of neutrophils cleared the human amyloid less efficiently than non-depleted mice.
Conclusions: Neutrophils may not directly mediate amyloid clearance through phagocytosis; however, these cells appear to act on the amyloid and function as a source of immune activation for professional phagocytes (e.g. macrophages), and in the absence of neutrophils amyloid clearance is markedly reduced.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Advances in fibril typing by LCMS/MS have improved the accuracy of amyloidosis diagnosis, revealing instances of dual amyloidogenic proteins within the same individual. However, reports of two different amyloidogenic proteins affecting the same organ are scarce in the literature.
We present a retrospective analysis of six cases of dual amyloidosis diagnosed at our center between 1995 and 2022. Diagnosis was confirmed through Congo red staining and fibril typing using the best available methods at the time. All cases underwent TTR gene testing.
Of the six cases, three (50%) exhibited AL amyloidosis alongside underlying B-cell lymphoproliferative disorders in conjunction with ATTRwt amyloidosis. Notably, one case demonstrated dual amyloidosis in a single endomyocardial biopsy, with clinical features indicative of ATTRwt-driven cardiomyopathy. Two additional cases were diagnosed with AL/ATTRwt and AA/ATTRwt amyloidoses, respectively, while one case presented with AIns and ATTRv amyloidoses. The time interval between the two diagnoses ranged from 1 to 24 years, with the heart and kidneys being the most commonly affected organs.
Our findings underscore the complexity of amyloidosis presentation, with multiple amyloid types potentially coexisting in an individual, either in the same or different anatomical sites. Accurate assessment of clinical phenotype and thorough amyloid fibril typing from various organs are essential for precise diagnosis and tailored treatment strategies.
Table 1. Characteristics of six cases with dual amyloidosis in one host.
Abstract
Topic: Treatments of ATTR
Background: Two outcomes trials demonstrate efficacy and safety of transthyretin protein (TTR) stabilizers in patients with established ATTR-CM. Acoramidis mimics the stabilizing effects of the T119M TTR variant, which is known to be protective in patients harboring the pathogenic V30M variant. Asymptomatic carriers of a pathogenic TTR variant represent a group in whom ATTR amyloidosis may be subclinical but risk for disease development is high. Trends in surveillance of asymptomatic TTR variant carriers suggest that individuals at higher risk for incident near-term disease can be identified. The ACT-EARLY trial aims to test the hypothesis that prophylactic treatment with next-generation TTR stabilizer acoramidis can prevent or delay development of ATTR amyloidosis in asymptomatic pathogenic TTR variant carriers.
Methods: ACT-EARLY is a prospective, multinational, randomized, double-blind, placebo-controlled study evaluating treatment with acoramidis in asymptomatic carriers of a pathogenic TTR variant. Eligible participants are aged 18–75 years with a known pathogenic TTR variant who are within 10 years of predicted age of disease onset for their specific variant. Approximately 500 participants will be randomized 1:1 to receive acoramidis or placebo for up to 5 years (Figure). Primary efficacy endpoint is time to development of ATTR amyloidosis (cardiomyopathy and/or polyneuropathy). Additional endpoints include safety and tolerability of acoramidis and its effects on cardiac imaging parameters, plasma TTR concentration, nerve conduction, and neurofilament light chain.
Results: See Figure: ACT-EARLY Study Schematic.
Conclusion: ACT-EARLY is the first phase 3 trial to evaluate prophylactic therapy for the prevention of ATTR amyloidosis. Enrollment will begin in 2024.
Abstract
Topic: Imaging
Subtopic: Cardiac
Cardiac amyloidosis (CA) is an infiltrative disorder caused by protein deposition, being transthyretin amyloidosis (ATTR) and primary amyloidosis (AL) the most common forms of CA. ATTR can occur in a hereditary form (ATTRv) or wild-type (ATTRwt). Our area is endemic for ATTRv due to the Val50Met mutation. Our purpose is to analyze the usefulness of scintigraphy with [99mTc]Tc-DPD (DPD-CS) in an endemic area and its relationship with the diagnostic of CA.
Retrospective study (04/2013–12/2022) of DPD-CS performed for suspected/screening of CA.Our acquisition protocol consists of performing planar images after 3h p.i. (anterior, left anterior oblique, left lateral) ± SPECT/CT. The assessment of myocardial uptake was evaluated using the Perugini scale (PS: 0–3), considering 2–3 as positive scans.
DPD-CS results were classified based on the suspicion of CA, according to the guidelines of the ESC 2021 (we considered cardiomyopathy if: LVH ≥12 mm + ≥3 signs/symptoms), as well as according to their final diagnosis: ATTRv, asymptomatic carriers, ATTRwt, AL, AA and other non-amyloid (NA) causes. Clinical findings were correlated with the results of the DPD-CS.
509DPD-CS were performed in 478 patients (median age: 73 years [22–95] ,62%men). Median follow-up: 4.17 years. 127/478 patients were classified with cardiomyopathy (131/509DPD-CS) and 351/478 without cardiomyopathy (378/509DPD-CS). 115/509positive-DPD-CS (PS-2:17,PS-3:98): 113 had cardiomyopathy (55-ATTRv,58-ATTRwt) and 2 without cardiomyopathy (1-ATTRv, 1-asymptomatic-Val50Met-carrier). These latter two patients developed cardiomyopathy during the follow-up. 394/509negative-DPD-CS (PS-0:387, PS-1:7):18 with cardiomyopathy (1-ATTRv,1-carrier,3-AL,13-NA) and 376 without cardiomyopathy (30asymptomatic-Val50Met-carriers,88-ATTRv,2-AA,9-AL,247-NA). The only patient with cardiomyopathy and ATTRv, had initial negative-DPD-CS with following positive-DPD-CS. All ATTRv without cardiomyopathy presented only polyneuropathic disease. Final diagnoses (according to DPD-CS number):146-ATTRv (144-Val50Met,2-Val142Ile),32-carriers,58-ATTRwt,12-AL,2-AA and 259-NA. The analysis obtained after correlating the results of the DPD-CS regarding the presence of cardiomyopathy was: sensitivity (86.25%), specificity (99.47%), PPV (98.26%), NPV (95.43%).
Our study reaffirms the usefulness of DPD-CS in the non-invasive diagnosis of cardiomyopathy due to ATTR.DPD-CS has an additional value in endemic areas for the early detection of CA in asymptomatic patients.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Recent studies have explored the diagnostic applications of [18F]-florbetaben PET/CT in cardiac light chain (AL) amyloidosis, yielding promising results. However, information on [18F]-florbetaben PET/CT as a tool for risk stratification is still missing. We aimed to examine the prognostic value of [18F]-florbetaben uptake in patients with cardiac AL amyloidosis (AL-CA).
Methods: Consecutive patients with biopsy-proven AL-CA received clinical and biohumoral evaluation and were submitted to [18F]-florbetaben PET/CT with a 60-min dynamic acquisition. Whole-heart static images were retrospectively reconstructed from the dynamic listmode acquisition between 50 and 60 min (late static). Late mean standardized uptake (SUVmean) was calculated. Patients were then followed-up for the endpoint of all-cause mortality.
Results: 40 patients (age 68 ± 10 years; 73% males) with AL-CA were recruited. During the follow-up, 23 patients (58%) died. The best prognostic SUVmean cut-off was calculated at 3.31 with Youden test after ROC analysis. Patients with high SUVmean (>3.31, n = 25) had a higher risk of death at Cox regression analysis (p = .004), as also shown by Kaplan Meier curves in Figure 1. This association was maintained after adjustment for age, sex and 2012 MAYO staging system (p = .030; HR 2.930, CI 0.196–3.865). At linear regression analysis, SUVmean was associated with hs-Troponin T (r = 0.420, p = .007) but not with N-terminal fragment of B-type natriuretic peptide (NT-proBNP, r = 0.278, p = .100).
Conclusions: High cardiac [18F]-florbetaben PET/CT uptake (SUVmean >3.31) may indicate a greater tissue damage (as reflected by higher troponin levels), and is an independent predictor of death in patients with AL-CA. [18F]-florbetaben PET/CT holds both diagnostic and prognostic value.
Abstract
Topic: Treatments of ATTR
Transthyretin (TTR) is an amyloidogenic protein associated with wild-type TTR (ATTRwt) amyloidosis and hereditary TTR (ATTRv) amyloidosis. Dissociation of the tetramer of TTR to the monomer causes TTR misfolding, which results in amyloid fibril formation. Stabilizers of tetrameric TTR were proposed as effective therapeutic agents to delay disease progression. However, the established drugs are more expensive and cannot be used as a prophylactic measure. Our study aimed to find a prophylactic supplement to prevent TTR amyloid formation. We investigated arginine to see whether it could stabilize tetrameric TTR and thereby inhibit amyloid fibril formation. We analyzed amyloidogenicity with a thioflavin T method and evaluated changes in the forms of TTR by western blot. The thioflavin T method showed that in the presence of arginine, the values were significantly suppressed compared with those without arginine. Western blot showed that arginine mixed with recombinant ATTRwt and ATTR V30M reduced the monomer level and increased the tetramer/monomer ratio of TTR compared with samples without arginine. In addition, arginine mixed with human serum samples increased the tetramer/monomer ratio of TTR compared with samples without arginine. Moreover, orally administered arginine to healthy volunteers effectively increased the serum arginine concentration and the tetramer/monomer ratio of TTR in serum. Our results suggest that arginine prevents TTR amyloid formation and stabilizes the tetrameric conformation. Because arginine is a safe substance and a commonly used supplement, it may be a promising supplement for prophylactic use to prevent amyloid fibril formation in ATTRwt amyloidosis and ATTRv amyloidosis.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Background/Aim: This study investigated the ability to categorize ATTR amyloidosis phenotypes using code-based segmentation algorithm.
Methods: Data from 2017 to 2022 were extracted from Optum’s de-identified Clinformatics® Data Mart Database (USA) and Medical Data Vision Database (Japan). Patients aged ≥18 years with an ICD-10 diagnosis code for ATTR amyloidosis (E85) or a claim for an ATTR-specific treatment were included. The overall cohort was segmented using diagnosis codes with details on classification, treatment or procedures indicating specific phenotype, as well as cardiac and neuropathy related diagnoses. This segmentation identified four groups: ATTR-cardiomyopathy (ATTR-CM), ATTR-polyneuropathy (ATTR-PN), ATTR with mixed phenotype and unknown. Patients with evidence of AA or AL amyloidosis were excluded.
Results: The predominant phenotype observed was ATTR-CM in both the USA (45.6%) and Japan (57.2%), followed by ATTR with mixed phenotype (USA: 34.2%, Japan: 10.2%) and ATTR-PN (USA: 4.3%, Japan: 3.0%). The proportion of unknown phenotype was 15.8% in USA and 29.6% in Japan. In Japan, patients with ATTR-CM and ATTR with mixed phenotype were predominantly male, whereas in the US, patients of all phenotypes were predominantly female, with those having ATTR-CM and ATTR with mixed phenotype being older. Additional demographic differences are illustrated in .
Table 1 Patient characteristics at diagnosis by phenotype in the USA and Japan.
Conclusions: These findings highlight a phenotypic heterogeneity associated with ATTR amyloidosis and differences between countries. Caution is required when categorizing ATTR amyloidosis by phenotype based on claims data given the absence of a gold standard algorithm for patient segmentation. Further analyses within the OverTTuRe study program, including validation studies are ongoing.
Abstract
Topic: Diagnosis ATTRwt
Background: Cardiomyopathy is the dominant feature of wild-type transthyretin (ATTRwt) amyloidosis. Involvement of other organs is uncommon.
Case presentation: We report the case of a 75-year-old male with 2-year history of progressive renal dysfunction and low-level proteinuria (). Renal biopsy demonstrated focal global glomerulosclerosis with ischemic changes, tubular atrophy, interstitial fibrosis, and arteriosclerosis. Additionally, the renal biopsy showed Congophilic deposits within arteriole walls but not within glomeruli. Weak-positive IgG kappa staining of these deposits by immunofluorescence suggested heavy and light chain (AHL) amyloidosis; however, no evidence of an underlying plasma cell dyscrasia was found ().
Bone marrow biopsy and abdominal fat pad aspiration both stained positive with Congo red. Immunogold electron microscopy of the fat aspirate revealed ATTR amyloidosis. Subsequent amyloid fibril typing of the renal biopsy using LCMS/MS identified only transthyretin peptides. Genetic testing was negative for transthyretin variants, confirming a diagnosis of ATTRwt amyloidosis.
Aside from renal manifestations, the patient had advanced congestive heart failure accompanied by active ischemic symptoms (); yet, he did not have characteristic features of ATTR-cardiomyopathy by technetium-99m pyrophosphate scintigraphy (). Transthyretin stabilizer therapy (tafamidis 61 mg daily) was initiated, but his condition deteriorated to end-stage renal disease. He developed cardiogenic shock due to unstable coronary syndrome and passed away 3 months after diagnosis.
Conclusion: This unique case illustrates the range of organ tropism that is possible in ATTRwt amyloidosis and underscores the importance of amyloid fibril typing using gold standard techniques for accurate diagnosis of amyloid [email protected]
Table 1. Clinical findings at the time of diagnosis with renal-predominant ATTRwt amyloidosis.
Abstract
Topic: Treatments of ATTR
Introduction: In the NEURO-TTRansform Phase 3 trial (NCT04136184), eplontersen significantly reduced neuropathy impairment and improved quality of life versus historical placebo in patients with hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN). To determine the impact of sex, this exploratory analysis evaluated the treatment effect of eplontersen in male and female patients.
Methods: Changes from baseline to Week 66 in modified Neuropathy Impairment Score +7 (mNIS +7) composite score (range, –22.3 to 346.3) and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QoL-DN) total score (range, –4 to 136) were measured, with higher scores indicating worsening neuropathy and poorer quality of life. Analyses were based on a mixed-effects model with repeated measures.
Results: Overall, 100 male and 44 female patients were randomized to receive eplontersen in the NEURO-TTRansform trial. Sixty patients (41 males, 19 females) from NEURO-TTR (NCT01737398) formed a historical placebo group. At baseline, in eplontersen versus placebo groups, respectively, male patients’ mean age was 51.7 versus 59.2 years, mean mNIS +7 composite score was 83.2 versus 78.5, and mean Norfolk QoL-DN total score was 44.7 versus 49.3; female patients’ mean age was 56.1 versus 60.3 years, mean mNIS +7 composite score was 76.9 versus 66.6, and mean Norfolk QoL-DN total score was 42.5 versus 47.4. Mean changes from baseline to Week 66 were lower (better) with eplontersen versus placebo for mNIS +7 composite score and Norfolk QoL-DN total score in both male and female patients (Figure).
Conclusions: Regardless of sex, eplontersen reduced neuropathy impairment and improved quality of life versus historical placebo in patients with ATTRv-PN.
Abstract
Topic: Pathology
In patients with cardiac amyloidosis (CA) several organs and tissues including tendons are often infiltrated by amyloid. Yet the prevalence of skeletal muscle infiltration in CA is not well known. Our aim was to define the prevalence of skeletal muscle amyloid infiltration in subjects with cardiac amyloid infiltration.
We re-examined the psoas muscle for amyloid infiltration using Congo Red staining in a consecutive autopsy series, with cardiac amyloid infiltration detected at time of autopsy. At the time of abstract submission, amyloid typing with Liquid Chromatography-Mass Spectrometry is pending.
We identified 20 patients with cardiac amyloid infiltration on autopsy: 65% male and median age of 83 years at time of death (). Two subjects had antemortem diagnosis of ATTR (n = 1) or AL amyloidosis (n = 1); typing pending in remaining. Skeletal muscle amyloid infiltration was seen in 80% (n = 16). Of those with skeletal muscle infiltration, 11 had a antemortem diagnosis of heart failure, 11 had atrial fibrillation/flutter, 7 had a prior cerebrovascular accident or transient ischemic attacks. Peripheral neuropathy had been documented in 5, spinal stenosis in 6 and carpal tunnel syndrome in 3. Of patients with cardiac and skeletal muscle amyloid infiltration, concurrent amyloid infiltration at autopsy was most common in the lungs (n = 10), followed by liver (n = 3), kidney (n = 2), small bowel (n = 1), and spleen (n = 1).
Table 1. Characteristics of subjects with and without skeletal muscle amyloid infiltration at autopsy.
Skeletal muscle amyloid infiltration was common in those with cardiac infiltration diagnosed at the time of autopsy. Whether skeletal muscle infiltration is a contributor to exercise intolerance, a cardinal feature of CA, needs to be studied.
Abstract
Topic: Diagnosis AL
Background: Small Fiber Neuropathy (SFN) is a known complication of AL amyloidosis but has not been systematically evaluated. Aim: To investigate the prevalence and clinical significance of SFN in patients with AL amyloidosis.
Methods: We prospectively evaluated 74 consecutive patients with newly diagnosed, previously untreated, AL amyloidosis (36 males, mean age 62.52 years, SD 9.86). The patients underwent neurological examination with Neurological Symptom Score, Neurologic Impairment Score, Quantitative Sensation Test (QST) and skin biopsy of the lower leg. Presence of Small fiber neuropathy (SFN) was defined as an abnormality of at least two clinical signs, intraepidermal nerve fiber density (IEFND) and QST results.
Results: SFN was detected in 68.5% (n = 50) of the patients; in 18 (36%) was associated with pain and was asymptomatic in 10% (n = 10). Follow-up and re-examination were performed 6–12 months following treatment initiation in 13 patients. All patients achieved bortezomib based regimens. No significant changes were observed in the clinical or electrophysiological findings at the timepoint of re-assessment. Reported symptoms did however deteriorate overall. The median follow-up of the cohort was 28.17 months; 26 patients (35%) have died. In univariate analysis, SFN was associated with shorter OS (p = .024) and early mortality <12 months (33% vs 4%, p = .007), among patients with heart involvement (Mayo stages 2 and 3).
Conclusion: Among AL patients the incidence of SFN is higher than previously estimated. Non-progression of neuropathy at reexaminations may indicate treatment response or disease stabilization. SFN seems to be an adverse prognostic factor and strong predictor of early mortality.
Abstract
Topic: Basic Science AL
A fraction of patients with immunoglobulin light chain (AL) amyloidosis who achieve a good hematologic response still experience an unfavorable clinical evolution due to progressive organ damage resulting from preexisting AL deposits for which current therapies are ineffective. Therefore, there is growing interest in therapies aimed at removing AL deposits by enhancing physiological mechanisms such as enzymatic degradation, cellular uptake, and clearance by specialized macrophage-like cells. Antibodies are ideal for this purpose, given their unique recognition properties and biological functions. However, clinical trials so far conducted with pan-AL fibril monoclonal antibodies have had mixed results. Low affinity and/or poor access to the target epitope may be the cause of their reduced therapeutic efficacy in some AL patients, a consequence of the high structural heterogeneity of AL fibrils. We postulate that antibodies with specificities restricted to structurally related light chains, such as those belonging to the same variable domain (VL) subgroup, may be more suitable for anti-AL fibril therapies than pan-AL antibodies. Using a structural approach, we produced six rabbit polyclonal antibodies (Ab-A to F) by immunizing animals with nonoverlapping peptide segments of the recombinant lambda-6 VL protein 6aJL2. We demonstrated that these antibodies recognize monomers, oligomers, and misfolded amyloid fibrils of 6aJL2 but not the native proteins. Furthermore, they recognized amyloid-like fibrils of AL-derived lambda-6 light chains with little or no cross-reactivity with aggregates of other kappa and lambda proteins (Figure 1). These findings indicate that this approach can be used to obtain AL subgroup-specific antibodies with therapeutic applications.
Abstract
Topic: Prognosis AL
Background: Sudden unexpected death (SUD) was the second leading cause of death in a prior 40-year natural history study of AL amyloidosis from our center. Here, we explored factors related to early-SUD.
Methods: We performed a review of patients with AL amyloidosis from 1980 to 2023 who suffered SUD using the database at the Boston University Amyloidosis Center. SUD was defined as unexplained death occurring within 1 h (witnessed) of symptom onset or within 24 h (unwitnessed) of being seen in normal condition, e.g. death during sleep. Causes of death were adjudicated by treating clinicians using information from medical records, family members and/or official death documents.
Results: Among 2794 patients, 1935 had died. Primary cause of death was ascertainable in 1291 cases, of which 280 (22%) were SUDs. The cumulative incidence of SUD at 1, 2 and 5 years of diagnosis was 5%, 7% and 9%, respectively. Nearly half (n = 138, 49%) of SUDs were early, i.e. within 1 year of diagnosis. Characteristics of patients suffering early-SUD are shown in , with a reference cohort of patients who survived or died of non-SUD causes during 1-year follow-up for comparison. Most (94%) patients suffering early-SUD had cardiac involvement. Gastrointestinal tract and autonomic nervous system involvement were also more common. Cardiac (BNP, troponin, BU stage), hemodynamic (syncope, blood pressure) and bleeding (factor X level) risk parameters were associated with early-SUD.
Table 1. An exploratory analysis of clinical factors associated with early (within 1 year of diagnosis) sudden unexpected death in systemic AL amyloidosis.
Conclusions: We identified clinical factors related to early-SUD in AL amyloidosis. More progress is needed in understanding potential underlying mechanisms and preventative management strategies.
Abstract
Topic: Basic Science AL
Background: The molecular machinery mediating immunoglobulin free light chain (FLC) secretion in AL is unknown. SNARE proteins are critical mediators of vesicular secretion in central nervous system. We investigate whether SNAREs are necessary for FLC secretion in AL.
Methods-Results: We identified SNAP23, VAMP3, and SYNTAXIN4 as top expressed SNAREs in plasma cells from AL/MM patients; confirmed their expression in cell lines via immunoblotting. As a tool to study SNARE function, we exploited the catalytic function of botulinum neurotoxin (BoNT), whose natural targets are SNAREs. We expressed 7 distinct, tetracycline-inducible BoNT serotypes (BoNT/A-F) with T2A-GFP in FLC-secreting AL(ALMC1/ALMC2) and MM(KMS11/U266) cell lines. We discovered that all BoNT serotypes, except BoNTB, led to rapid apoptosis of AL/MM cells; dual cleavage of SNAP23/VAMP3 correlated with cytotoxicity. Immunofluorescence and electron microscopy imaging showed that cytotoxic BoNTs led to distortion of Golgi and accumulation of large secretory vesicles with evidence of decreased FLC secretion and increased FLC retention. At molecular level, cytotoxic BoNTs induced the terminal branch of the unfolded protein response with CHOP/GADD34 expression and ER-resident caspase cleavages. We identified SNAP23 as an interacting partner of cytotoxic BoNTs via proximity-labeling. SYNTAXIN4 was subsequently identified as interacting partner of SNAP23. SNAP23 knock-out was partially cytotoxic to AL cells, suggesting the need for concomitant targeting of multiple SNAREs.
Overall, our data point toward a critical role for SNAP23-mediated SNARE complex in FLC secretion. We provide proof of concept that its inhibition leads to catastrophic proteotoxic stress and apoptosis in AL/MM cells, laying the foundation for therapeutic development of SNARE inhibitors.
Copyright for this individual abstract is: © 2024 Brigham and Women’s Hospital. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Diagnosis ATTRwt
Background: Wild-type transthyretin (ATTRwt) amyloidosis is a systemic disease. Extracardiac tissues/organs are sometimes the first site of disease identification. This study explores the spectrum of tissues/organs where ATTRwt amyloid deposits are identified and describes the outcomes of patients with non-cardiac disease.
Methods: We studied 552 patients with ATTRwt amyloidosis seen at the Boston University Amyloidosis Center between 1994–2023 who had at least one tissue/organ biopsy stained with Congo red (CR). Median number of tissue samples per patient was 2 (total 957 biopsies). Amyloid typing and genetic analysis were performed to confirm diagnosis.
Results: The endomyocardium and abdominal fat pad-stained CR positive in 99% (203/205) and 23% (123/534) of biopsy samples, respectively. Common extracardiac sites where ATTRwt amyloidosis was detected included the tenosynovium, bone marrow, gastrointestinal tract, lungs, and urinary bladder (). Of 119 patients with positive CR staining of extracardiac biopsy sites, 68 (57%) had ATTR-cardiomyopathy at the time of extracardiac biopsy; whereas 51 (43%) did not, of whom 6 (12%) subsequently developed ATTR-cardiomyopathy after a median of 2.4 years (range 0.4–22.7).
Table 1. The spectrum of extracardiac tissue/organ sites where ATTRwt amyloid deposits were identified.
The 45 patients who did not develop ATTR-cardiomyopathy (median follow-up of 1.8 years, range 0.2–10.3) were younger (73 vs 76 years, p < .001) and more often female (18% vs 6%, p = .002) than those with ATTR-cardiomyopathy. Median overall survival was 6.8 years (95%CI, 3.3-NR) for this non-cardiac group and 4.3 years (95%CI, 3.8-4.6) for those with ATTR-cardiomyopathy (p = .059).
Conclusions: ATTRwt amyloidosis is commonly identified in extracardiac tissues/organs. Some patients lack clinical features of ATTR-cardiomyopathy and have favorable outcomes.
Abstract
Topic: Treatments of AL
Clinical trials (CTs) have helped pave the way for treatment of AL amyloidosis over the years. Despite notable progress, challenges persist in research, with regard to patient enrollment. This abstract outlines the portfolio of AL amyloidosis CTs at our center during the past three decades and identifies recent impediments to recruitment.
Between 1994 and 2023, a total of 632 participants with AL amyloidosis were enrolled in CTs at the center. There were 12 CTs of stem cell transplantation (SCT) with 341 participants and 24 CTs of non-SCT therapies with 291 participants. The majority of SCT-CTs were investigator-initiated trials (IIT; n = 11); only one was a cooperative group conducted trial. Meanwhile, 10 of the 24 non-SCT-CTs were industry sponsored; 8 were IIT; 4 were multicenter IIT; and 2 were cooperative group conducted trials. Representation of racial/ethnic minorities in all trials was 11% (n = 70), including 38 (6%) participants who self-identified as Non-Hispanic Black and 19 (3%) as Hispanic.
Over the last 5 years (2018-2023), 130 patients were prescreened for 9 non-SCT treatment CTs, of whom 79 (61%) failed recruitment (). The most common reasons affecting enrollment were: patient preference due to trial protocol logistics (27%); dFLC not meeting eligibility (18%); cardiac biomarkers out of range (16%); and failure to meet other CT inclusion criteria (20%).
Table 1. Common reasons for barriers to recruitment on clinical trials from 2018 to 2023.
In conclusion, many participants have successfully enrolled in numerous CTs at our center, despite AL amyloidosis being a rare disease. Minority accrual was low. Both patient-related and protocol-related (i.e. restrictive inclusion criteria) factors frequently impeded CT participation.
Abstract
Topic: Basic Science ATTR
ATTR amyloidosis is caused by the conversion of soluble transthyretin into amyloid fibrils that accumulate in affected organs leading to premature death. This conversion is facilitated by mutations in the ttr gene in variant ATTR (ATTRv) amyloidosis or by unknown aging-related factors in wild-type ATTR (ATTRwt) amyloidosis. While ATTRwt patients typically present with major cardiac involvement later in life, ATTRv patients exhibit considerable symptom variability, often involving neuropathy symptoms and occurring as early as the age of 25. Multiple studies in neurodegenerative diseases suggest that structural differences in the amyloid fibrils found in the brain determine the clinical diagnosis. To explore this hypothesis in ATTR amyloidosis, we use cryogenic electron microscopy to determine and compare the structures of cardiac fibrils extracted from various patients with cardiomyopathy, neuropathy, or a mixed phenotype, and with various genotypes (ATTRwt, ATTRv-P24S, ATTRv-A25S, ATTRv-V30M, ATTRv-T60A, ATTRv-V122I, ATTRv-I84S). We also compare the structures of ATTR fibrils from the heart and the nerves from the same ATTRV30M patient. Remarkably, all neuropathic ATTRI84S patients exhibit fibril structural polymorphism; shown among different individuals and within the same fibrils. In contrast, cardiomyopathic or mixed patients exhibit similar fibril structures across different mutations. The fibril structure extracted from ATTRV30M nerves also resembles that of the cardiomyopathic type. Further studies are warranted to determine the implications of our findings.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Transthyretin (ATTR) amyloidosis is an increasingly recognized disease that can cause organ dysfunction, leading to significant morbidity and mortality. The SF-36v2® Health Survey (SF-36v2®) was previously tested and validated as an indicator of health-related quality of life (HRQoL) in AL amyloidosis. Its relevance to patients with variant (ATTRV122I and non-V122I-ATTRv) and wild-type (ATTRwt) ATTR amyloidosis has yet to be evaluated.
Methods: We retrospectively retrieved initial SF-36v2® scores for patients with ATTR amyloidosis evaluated at the Boston University Amyloidosis Center between 1971 and 2022 and assessed average deficits in the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores relative to general U.S. population norms.
Results: In total, 836/1037 (80.6%) patients with ATTR amyloidosis had a baseline SF-36v2® score, of whom 407 (48.7%) had ATTRwt amyloidosis, 336 (40.2%) had non-V122I-ATTRv amyloidosis, and 93 (11.1%) had ATTRV122I amyloidosis. Patients’ PCS scores (ATTRwt: 36, non-V122I-ATTRv: 37, ATTRV122I: 33) were lower than the average adult (50), indicating worse physical health status, with role limitations due to physical health and energy/fatigue being the most impaired domains. Patients’ MCS scores (ATTRwt: 51, non-V122I-ATTRv: 50, ATTRV122I: 49) were comparable to the average adult (50), indicating similar mental health status.
Conclusions: Patients with ATTR amyloidosis had impaired physical health relative to the average adult as indicated by SF-36v2® PCS scores. Those with ATTRV122I amyloidosis had the lowest PCS scores. Additional longitudinal analyses are needed to assess the stability of scores over time and to identify predictors of physical and mental health within each clinical subtype.
Figure 1. Physical Component Summary (PCS) and Mental Component Summary (MCS) scores based on results of the SF-36v2® Health Survey among patients with ATTR amyloidosis relative to the average U.S. adult.
Abstract
Topic: Basic Science AL
Background: Light chain research is hampered by lack of mammalian cell lines producing human light chains (FLC). Therefore, we used heterohybridoma (HH) technology and CD138-selected marrow cells to produce clones making FLC.
Methods: Marrows from patients with disease due to AL, myeloma (MM) and polyclonal gammopathy (PG) obtained via IRB protocol had CD138+ cells selected, fused with B5-6T cells, and HAT-cultured. HH clones were selected based on ELISA for human immunoglobulins (huIg) and flow cytometry for intracellular (IC) FLC. We compared marrow cell counts and HH yields by diagnosis, evaluated clones making only FLC by flow and by dimer/monomer (D/M) ratios in vitro and in vivo (NSG mice), and sequenced FLC genes with RT-PCR.
Results: Marrows from 44 patients with active disease, 30 AL, 10 MM and 4 PG were no different in CD138+ cell counts. HH FLC clones (7 λ, 1κ) were obtained from 0/30 AL and 7/14 MM + PG (p < .01, Fisher’s exact test). Median MFI by IC flow for FLC was 9849 (5344–27,451). Data on these clones are tabulated below.
Conclusions: B5-6T HH producing human FLC were obtained from 50% of MM and PG cases and will be made available for research. Our efforts were unsuccessful in 30 AL cases. We are investigating a role for polyethylene glycol (PEG) interacting with FLC during fusion. PEG is a polysaccharide, an AA-enhancing agent in vivo, and also binds to the amyloid-beta peptide; it may cause aggregation of AL FLC impairing successful fusion. We are now exploring electrofusion for AL CD138+ cells.
Abstract
Topic: Prognosis ATTR
Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an infiltrative process with poor prognosis when left untreated. Despite the approval of tafamidis therapy, significant knowledge gaps exist regarding its use. This project determined baseline predictors of all-cause and cardiovascular mortality and hospitalization, as well as the associations of these predictors to therapy in a clinical cohort from an ATTR-CM referral center. It was hypothesized that select baseline variables will be associated with mortality and the need for hospitalization after the initiation of targeted ATTR-CM therapy.
Methods: Multivariable modeling was performed with backward stepwise selection to obtain predictors for each event, considering only those variables that demonstrated statistical significance in the univariable analysis. Cox proportional hazard or competing risk regression were used, with ATTR-CM therapy modeled as a time-varying covariate.
Results: A total of 145 patients with ATTR-CM were identified from 2011 to 2021. Eighty (55%) patients were treated with tafamidis. After 2.9 ± 1.8 years of follow-up, there were a total of 58 death events, of which 49 deaths were cardiovascular-related. The likelihood of experiencing all-cause or cardiovascular mortality increased with advancing age, greater frailty, and impaired renal and right ventricular function (all p < .05, Table 1), however no interactions with treatment were identified. Kidney function significantly interacted with treatment for cardiovascular hospitalization, such that lower eGFR at baseline was associated with less benefit from therapy (HR [95% CI], 0.93 [0.87–0.99], p < .05).
Conclusion: Important baseline criteria associated with ATTR-CM disease prognosis and major adverse events included age, renal function, frailty, and right ventricular function.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an increasingly recognized condition with poor prognosis without treatment. The incorporation of tafamidis therapy into clinical practice has been challenging as surveillance testing and monitoring approaches vary widely. This project determined factors that predict a beneficial response to tafamidis by assessing the magnitude and timing of change across clinical, biochemical, and cardiac imaging domains.
Methods: We collected baseline and serial parameters associated with ATTR-CM disease burden. Baseline variables were correlated with the occurrence of study endpoints, and with subsequent change in serial measures of disease burden.
Results: A total of 145 patients with ATTR-CM were identified from 2011 to 2021. Baseline Troponin T was significantly lower in patients receiving tafamidis at baseline [median (Q1–Q3), 40.0 ng/L (32.0–66.0 ng/L) (n = 23) and 71.5 ng/L (54.0–128.0 ng/L) (n = 18), for patients on and not on tafamidis, respectively (p < .05)], and at 1-year follow-up. NTproBNP was also significantly lower at baseline for those treated [median (Q1–Q3), 2810 ng/L (659.5–4389.5 ng/L) (n = 28) versus 5436.0 ng/L (1648.0–10,950.0 ng/L) (n = 23) (p < .05)], but not at 1-year follow-up. Both tafamidis and baseline NYHA class of II or III were found to be significant predictors of NYHA class at 1-year follow-up [OR (95% CI), tafamidis: 0.39 (0.20–0.77), baseline NYHA II and III: 18.83 (6.90–51.39) and 120.02 (38.86–370.71), respectively].
Conclusion: Over the course of 1 year, patients treated with tafamidis demonstrated stabilization in NTproBNP, Troponin T, and NYHA functional class, while those untreated experienced significant worsening in cardiac biochemical markers.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is a progressive infiltrative process with variable approaches to disease monitoring. The NAC and Mayo staging systems are used to assess ATTR-CM disease severity at diagnosis; however, these tools were validated prior to the availability of tafamidis. This study evaluated change in the NAC and Mayo staging system for patients treated and untreated with tafamidis from baseline to 1-year follow-up.
Methods: We collected baseline and serial markers to categorize patients according to NAC and Mayo staging system criteria. Ordinal logistic regression was used to assess whether tafamidis was associated with ATTR-CM disease stage at 1-year follow-up, controlling for baseline NAC and Mayo stage.
Results: A total of 145 patients with ATTR-CM (126, 87% men, 19 women; mean age at diagnosis 79.1 ± 0.7 years) were identified from 2011 to 2021. Eighty (55%) patients were treated with tafamidis. While not statistically significant, both NAC and Mayo stages remained stable in treated patients but trended toward progression in untreated patients after 1-year. A larger proportion of untreated patients were in NAC and Mayo stage III compared to treated patients at 1-year (Table 1). Baseline Mayo stage II patients had no significant progression at 1-year follow-up, irrespective of tafamidis status, while baseline NAC stage II patients did progress, suggesting NAC stage may be more sensitive in detecting disease progression.
Conclusion: Among ATTR-CM patients, Mayo and NAC stages trended stable at 1-year follow-up for tafamidis-treated patients, with progression in untreated patients.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an infiltrative process with poor prognosis when left untreated. While Health Canada defines clinical eligibility criteria for initiating therapy, some patients, despite meeting these criteria, may derive limited or no benefit from treatment. This study aimed to identify parameters that can be used to assess the clinical decision-making process for initiating or withholding therapy in ATTR-CM patients.
Methods: Baseline parameters associated with ATTR-CM disease burden were collected, and logistic regression was employed to evaluate how these factors influenced the likelihood of treatment initiation.
Results: A total of 145 patients with ATTR-CM were identified from 2011 to 2021. Patients initiated on therapy were younger at diagnosis [77.1 years (69.6–83.2 years) (n = 86)] compared to those not on therapy [86.3 years (79.1–88.8 years) (n = 59)] (p < .05). Frail (clinical frailty scale score >4) patients demonstrated a 78% reduction in the likelihood of treatment initiation (p < .05). Additionally, treated patients had lower baseline NTproBNP [2863.0 ng/L (1094.0–4061.0 ng/L) (n = 59)] and Troponin T [54.5 ng/L (35.0–74.0 ng/L) (n = 50)] values compared to untreated patients [6179.5 ng/L (2913.0–10,872.0 ng/L) and 86.0 ng/L (56.0–132.0 ng/L), respectively] (both p < .05). Those with a baseline NYHA functional class of ≥ III were 67% less likely to undergo therapy initiation. Treated patients also exhibited significantly fewer comorbidities compared to the untreated group.
Conclusion: Patients with frailty or more advanced ATTR-CM disease status at baseline were less likely to be initiated on therapy, potentially indicating a reduced likelihood of benefiting from treatment due to the progressive nature of this disease.
Abstract
Topic: Diagnosis ATTRv
Background: Amyloidosis involves abnormal protein deposition in various organs, including the heart. Associated features, including carpal tunnel syndrome (CTS) and lumbar spinal stenosis, can raise suspicion for diagnosis. Mitral regurgitation (MR) is often noted in cardiac amyloidosis (CA) patients. We describe a case of primary-MR, subsequently diagnosed with transthyretin amyloidosis (ATTR), causing hemodynamic compromise post-valve surgery.
Case: 73-year-old Black male with hypertension, left-ventricular hypertrophy (LVH), bilateral CTS, MR presented with progressive NYHA class-III symptoms and signs of heart failure. Echocardiogram showed severe-MR, EF =55%, dilated-LA, LVH, mild-to-moderate tricuspid regurgitation. CCTA revealed no significant CAD. Given EF <60%, he underwent primary mitral valve replacement with tricuspid valve repair. Intra-operatively, biventricular hypertrophy prompted endomyocardial biopsy of right ventricle and interatrial septum revealing ATTR, while mitral valve exhibited myxoid degeneration. Post-operatively, he developed cardiogenic shock requiring prolonged inotropic support, with EF =36%. Genetic testing was negative, confirming wtATTR.
Discussion: Undiagnosed CA with resultant low cardiac output caused persistent shock post-surgery, thus, prolonging intensive care and hospital stay. This case underscores the importance of early CA diagnosis, anticipating such scenarios, and planning of appropriate interventions prior to surgery. It also emphasizes the importance of maintaining high suspicion for CA, particularly in patients exhibiting echocardiographic signs like restrictive heart disease, LVH, and systemic associations like CTS.
Conclusion: While uncommon, primary valve disorders may coincide with underlying CA. Suspecting CA in patients exhibiting LVH and associated systemic signs is crucial. Early CA detection aids in post-operative management, particularly in patients with mitral surgery, where acute changes can affect intracardiac physiology.
Abstract
Topic: Basic Science AL
Each clonal light chain (LC) that aggregates in AL amyloidosis has a unique protein sequence. These sequences are publicly available online in AL-Base, which was recently updated: https://wwwapp.bumc.bu.edu/BEDAC_ALBase/
Defining links between LC sequence and pathology could aid early diagnosis and lead to new therapies. To identify unique features of AL-associated sequences, germline gene use and somatic mutations were compared between AL (n = 809), multiple myeloma (MM, n = 1175) and the polyclonal repertoire, derived from the Observed Antibody Space resource (OAS, n = 8,047,747). Sixteen precursor genes were enriched in AL versus MM (shown in the Figure). For AL versus OAS, ten genes (IGLV6-57, IGLV3-1, IGKV1-33, IGKV1-16, IGLV1-36, IGLV1-44, IGLV1-51, IGLV2-14, IGLV3-19, and IGLV3-21) were enriched and two (IGKV3-20 and IGKV3-11) were significantly under-represented. AL-associated kappa and lambda LCs had medians of 11 and 10 mutated residues, respectively, compared to 10 and 12 mutations for MM LCs. These values were statistically significant but unlikely to be biologically meaningful. Individual mutations occurred throughout AL sequences with little evidence for mutational ‘hotspots’. N-glycosylation sequence motifs (NxS/T sequons) were present in 41% of AL kappa LCs, versus 10% of MM kappa LCs and 7.5% of OAS kappa LCs, consistent with a potential role in pathogenesis. Sequon frequencies for AL, MM and OAS lambda LCs were 7.3%, 10% and 6.8%, respectively. The LICTOR, Ab-Amy and VL-AmyPred algorithms had lower accuracy on sequences not used for their development. This analysis demonstrates that sequence determinants of amyloidosis are complex, and that more data are needed to predict amyloidosis risk.
Abstract
Topic: Diagnosis ATTRwt
Background: Transthyretin amyloidosis (ATTR) is an underdiagnosed and underestimated cause of heart failure and polyneuropathy. ATTR can be familial (ATTRm) caused by misfolding of mutated transthyretin or wild-type (ATTRw) caused by misaggregation of genetically normal transthyretin. ATTRw is most often found to be concentrated in the heart, however, patient presentations can mimic ATTRm. We present three unique cases that demonstrate unusual deposition of ATTRw.
Case presentations: Case one: 72-year-old female with polyneuropathy was referred for leukopenia and anemia. Bone marrow biopsy was negative for light chain plasma cells, mass spectrometry identified ATTR (Figure 1A). Cardiac nuclear PYP grade 0.
Figure 1. Congo red stain of biopsies under polarized light. Congo red stain with apple-green birefringence under polarized light of bone marrow biopsy (A) and bladder biopsy (B).
Case two: 83-year-old male with bilateral carpal tunnel referred for gross hematuria. Found to have a bladder mass, biopsy followed by mass spectrometry positive for ATTR (Figure 1B). Cardiac PYP grade 3.
Case three: 66-year-old male with chronic atrial fibrillation was referred for progressive bilateral lower extremity weakness. Muscle biopsy followed by mass spectrometry was positive for ATTR. Cardiac PYP grade 2. Genetic testing revealed normal transthyretin in all three cases leading to a diagnosis of wild-type transthyretin amyloidosis.
Conclusion: These cases highlight the variability of ATTRw tissue deposition leading to a variety of clinical presentations and diagnostic challenges.
Abstract
Topic: Diagnosis ATTRv
Objective: We compared the gold standard single molecule array (Simoa) assay and Meso Scale Discovery (MSD) R-PLEX assay for measuring serum neurofilament light chain (sNfL), an early and sensitive biomarker of polyneuropathy. We aimed to identify a high performance and well accessible assay for sNfL measurement in hereditary transthyretin (ATTRv) amyloidosis.
Methods: sNfL levels were measured in serum samples collected between January 2000 and December 2021 from pathogenic transthyretin gene (TTR) variant carriers and ATTRv amyloidosis patients. In each sample, sNfL levels were assessed using both the Simoa and MSD R-PLEX assays allowing direct comparison of the assays.
Results: A total of 332 samples were evaluated in 72 subjects. sNfL levels measured with the MSD R-PLEX assay (median 128.7 pg/mL, interquartile range (IQR) 58.8–279.3) were consistently 4.9 times higher than those measured by the Simoa assay (median 26.4 pg/mL, IQR 11.3–50.2), p < .0001. A strong correlation was found between levels measured with both assays (Pearson correlation coefficient 0.93, p < .0001) (Figure 1). Bland-Altman analysis showed, within the 95% limit of agreement, a mean constant bias of 130.4% for sNfL concentrations determined by the MSD R-PLEX assay compared to the Simoa assay. The quantitative difference between the assays seems related to the internal reference provided with the tests. This study will be expanded with sNfL levels of healthy controls.
Conclusion: The MSD R-PLEX assay emerges as a robust and sensitive alternative to the Simoa assay for measuring sNfL in ATTRv amyloidosis.
Copyright for this individual abstract is: © 2024 University Medical Center Groningen. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Treatments of ATTR
Background: Patisiran is an RNA interference therapeutic approved for ATTRv amyloidosis. Patisiran was shown to halt or inhibit progression of neuropathy and cardiomyopathy, however, little is known about its effect on reduction of amyloid deposition.
Objective: To elucidate the effect of patisiran on reduction of amyloid deposition.
Methods: Amyloid deposition was assessed by gastroduodenal biopsy (N = 19) and 11C-Pittsburgh compound B (11C-PiB) PET (N = 6) before and after 2 years of patisiran treatment. In the biopsy analysis, % area of amyloid deposition in the gastroduodenal mucosa was quantified by Congo red staining. In the 11C-PiB PET analysis, Myocardium/Background Ratio (MBR) was used, defined as (standardized uptake value (SUV) myocardium/SUV background).
Results: In the biopsy analysis, % area of amyloid deposition in the gastroduodenal mucosa following 2 years of patisiran treatment (1.07 ± 1.28) was significantly lower than that at baseline (4.18 ± 3.70; p = .0004, paired t test). Amyloid deposition disappeared in 3 patients. Mean % amyloid reduction with patisiran was 60.2 ± 35.7%. In the 11C-PiB PET analysis, MBR at 2-year follow-up (2.82 ± 0.82) was significantly lower than that at baseline (4.01 ± 1.24; p = .007, paired t test). Mean % MBR reduction with patisiran was 28.7 ± 16.7%.
Discussion and Conclusions: Patisiran significantly reduced amyloid deposition in the gastroduodenal mucosa and heart. Our results suggest the existence of an intrinsic ATTR amyloid degradation system in the human body since a reduction in amyloid deposition was observed by inhibiting production of TTR.
Copyright for this individual abstract is: © 2024 Shinshu University. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Diagnosis ATTRwt
Background: Although most patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) are diagnosed noninvasively, concerns have been raised that many may be receiving the diagnosis with incomplete evaluations (i.e. not based on consensus recommendations). Using a cohort of US Medicare fee-for-service patients, we explored the frequency and cadence of diagnostic testing for ATTRwt-CM.
Methods: In this retrospective observational study, administrative de-identified claims data were derived from patients aged ≥65 years who had ≥1 claim for ATTRwt-CM and heart failure or cardiomyopathy, and ≥2 years of continuous Medicare enrollment before the first ATTRwt-CM diagnosis. Patients with claims for any other form of amyloidosis, multiple myeloma, or plasma cell dyscrasias were excluded.
Results: Among 2050 patients with ATTRwt-CM, mean (SD) age was 80.0 (6.9) years, and 75.5% were men. Less than half of these patients had serum free light chain testing (46.2%), and about one-fifth had complete monoclonal protein testing (21.5%). A small minority (14.4%) underwent recommended noninvasive diagnostic testing comprised of complete monoclonal protein testing and PYP scintigraphy. Total new ATTRwt-CM diagnoses/year nearly tripled from 2018 (n = 198) to 2022 (n = 578 [Figure]). Cardiac biopsy use declined from 14.1% in patients diagnosed in 2018 to 5.4% in those diagnosed in 2022. Technetium-99m pyrophosphate (PYP) scintigraphy use peaked in patients diagnosed in 2020 (52.3%); it was performed in approximately half of diagnosed patients by the end of the study period (2018, 30.3%, 2022, 49.0%).
Discussion: Based on Medicare claims data, most patients diagnosed with ATTRwt-CM have not been diagnosed utilizing consensus recommended pathways.
Abstract
Topic: Treatments of AL
AL amyloidosis (AL) typically originates from plasma cell (PC) clones producing amyloidogenic light chains. These are distinct in proliferation, paraprotein production, and cytogenetics. Differences in PC biology affect prognosis and may imply different therapeutic strategies.
We retrospectively studied 378 patients with biopsy-proven systemic PC-derived AL from January 2006 to December 2023 that received HD or triplet /quadruplet therapy. HD-uneligible and myeloma patients were excluded.
54 patients received high-dose (HD) melphalan (median 140 mg/m²), 52 were treated without HD. They were evenly distributed for cardiac involvement (53%, median Mayo stage II), BMPC (13/11%), lambda phenotype (80/85%), and t(11;14) (53%). An R2ISS high-risk phenotype was prevalent in 23/30%. Serologic response (69/75% ≥VGPR) and cardiac response (32/27% ≥VGPR) were similar. No patients were transplanted due to progression.
Median PFS/OS were not different (p = .7/0.6) after a median follow-up of 47 months. Patients with HR had poorer PFS (134/60 months, p = .02). BMPC >10% predicted PFS (84/45 months, p = .05). R2-ISS and dFLC did not differentiate PFS/OS.
Patients without HR/BMPC >10% benefited from intensive therapy: patients with HD had better PFS (124/56 months, p = .04). Quadruplets provided longer PFS (nr/56 months, p = .03). Patients with HR had poorer PFS (28/123 months, p = .04) but a trend to benefit from HD (PFS 30/13 months, p = .09). Quadruplets did not overcome HR (PFS 18/31 months, p = .02).
Overall, in a well-defined cohort, patients without HR/BMPC >10% showed significant PFS benefit from both HD and quadruplets. In patients with HR, only HD was able to ameliorate the poor prognosis, suggesting an important role for myeloma-derived cytogenetics in AL therapy planning.
Abstract
Topic: Treatments of AL
Introduction: The addition of daratumumab to bortezomib-cyclophosphamide-dexamethasone (VCD) significantly improved outcomes for treatment-naïve AL in ANDROMEDA. An immunomodulatory agent-based quadruplet has not been investigated as first-line treatment in AL. We report the UK experience of daratumumab-bortezomib-thalidomide-dexamethasone (DVTD) in patients with treatment-naïve AL amyloidosis.
Methods: Treatment-naïve patients with systemic AL between 2021 and 2023 proceeding with DVTD were retrospectively reviewed from the UK National Amyloidosis Centre. Daratumumab was administered for 4 cycles (weekly subcutaneous 1800 mg, cycles 1–2; biweekly cycles 3–4) with 6 cycles subcutaneous bortezomib (1–1.3 mg/m2 weekly) and thalidomide (D1–28 50 mg, omitted in cycle 1). Individual clinicians modified doses as per patient tolerance.
Results: Ninety-nine patients (62 M, 37 F) commenced DVTD. Baseline characteristics are outline (). Median follow-up was 10 (0–26) months; a median of 6 (0–8) cycles were delivered. By intention-to-treat analysis, best hematological responses were CR:61%, VGPR:20%, PR:15%, NR:4% at a median of 6 (1–66) weeks in responders. Nine patients died (Mayo IIIb: 3; IIIa: 4; II: 2); 2/9 due to unrelated malignancy whilst in VGPR/CR. Six proceeded with HDM-ASCT consolidation after DVTD induction. Overall, 6 patients (CR:1, VGPR:3, PR:2) progressed, requiring second-line IMiD-based therapy. Median OS was not reached for any Mayo subgroup. Estimated 1-year OS was 89% (95% CI 78–94) and for Mayo I, II, IIIa, IIIb was 100%, 93%, 79%, 82%. Estimated 1-yr treatment-free-survival/death was 79% (95% CI 67–88).
Table 1. Patient characteristics.
Conclusion: This series supports the use of dose-modified DVTD in first-line AL amyloidosis including in those with Mayo IIIb/renal impairment, with rapid and deep responses achievable, comparable with DVCD.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
The decedent was an 81-year-old man who succumbed to disseminated Nocardia infection from chronic immunosuppression for sarcoidosis. At autopsy, systemic amyloidosis was identified involving the heart, liver, kidneys, adrenal glands, testes, lymph nodes, dura mater and vasculature.
Formalin-fixed paraffin embedded (FFPE) tissue was sent to Mayo Clinic Laboratories for amyloid typing by mass spectrometry. The proteomic profile supported the diagnosis of amyloidosis and showed a disproportionately high number of ApoA1 peptides. However, no amino acid sequence variant was detected by routine bioinformatics analysis. The raw mass spectrometry data were subjected to a novel bioinformatics analysis configured to look for both unexpected posttranslational modifications and single nucleotide polymorphisms using DirecTag-TagRecon-IDPicker pipeline. This analysis revealed an unusual peptide hosting an oxidation of tryptophan (+16 Da) along with a known amyloidogenic mutation p.Leu99Pro. The presence of these sequence modifications rendered the mutant peptide undetectable by routine bioinformatics.
Since the patient was deceased, a FFPE tissue-based DNA sequencing method was used to verify the mutation. DNA was extracted from five 10-micron scrolls from an FFPE block containing spleen and lymph node tissue of the decedent. Subsequent PCR amplification of the DNA product generated a 305 base-pair fragment encompassing the region of interest. Sanger sequencing revealed a heterozygous c.296 T > C nucleotide transition in APOA1 (NM_000039.1), confirming the presence of a p.Leu99Pro missense variant in apolipoprotein A1.
The ability to identify the amyloid type was of critical importance to the patient’s surviving family members, allowing them to assess and manage their risk of hereditary amyloidosis.
Abstract
Topic: Treatments of ATTR
Background: Racial/ethnic minorities have been underrepresented in population studies and clinical trials for transthyretin (ATTR) amyloidosis. With scarce information about disparities in this disease, we aimed to characterize ATTR treatment utilization across racial/ethnic groups.
Methods: Data were collected from the clinical database of consented patients with ATTR amyloidosis evaluated at the Boston University Amyloidosis Center between 1971 and 2022. We analyzed use of ATTR therapeutics according to self-reported race/ethnicity. Groups included non-Hispanic White (NHW), non-Hispanic Black (NHB), Hispanic, and non-Hispanic other (NHO).
Results: Among 1037 patients with ATTR amyloidosis, 198 (19.1%) were underrepresented minorities (NHB, Hispanic, NHO), while 839 (80.9%) were NHW. Racial/ethnic minorities comprised an increasing proportion of the patient population over time: pre-2000: 13.3%; 2000–2010: 17.3%; 2011–2017: 19.7%; 2018–2022: 22.3%. ATTR amyloidosis sub-classifications among minorities included ATTRV122I (n = 134, 67.7%); non-V122I-ATTRv (n = 38, 19.2%); and ATTRwt (n = 26, 13.1%) amyloidosis. Collectively, 589 (56.8%) patients received ≥1 ATTR therapy (i.e. stabilizers, silencers, supportive treatment); the proportion was lowest among NHBs at 43.9%. We found that 33.1% of NHBs and 40.6% of Hispanics received TTR stabilizers as compared to 43.5% of NHWs (p < .05* and p = .899, respectively). Additionally, 10.8% of NHBs and 6.3% of Hispanics received TTR silencers as compared to 11.2% of NHWs (both p > .5).
Conclusions: These data indicate that racial/ethnic disparities exist in ATTR amyloidosis. Despite increasing referral of minorities in more recent years coinciding with ATTR therapy availability, use of ATTR stabilizers was significantly lower among NHB patients. Prohibitive cost and access barriers could be contributing to this finding.
Table 1. Comparison of sociodemographic factors, disease characteristics, and use of ATTR therapeutics by self-reported race/ethnicity.
Copyright for this individual abstract is: © 2024 Analysis Group. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Treatments of ATTR
Background: Patients with cardiac amyloidosis (CA) often experience heart failure (HF) episodes. No evidence is available on inotropic therapy. This study aims to fill this gap by examining the safety and efficacy of levosimendan.
Methods: We retrieved all HF patients receiving ≥1 levosimendan infusion from 2013 to 2023. CA patients were matched with HF patients without CA (controls) based on sex, age, and left ventricular ejection fraction (LVEF). The response to levosimendan was measured as changes in daily urinary output, body weight, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and estimated glomerular filtration rate (eGFR).
Results: CA patients (median age 77 years, 73% men, 59% with ATTR-CA) and controls were compared. Levosimendan infusion was stopped because of hypotension in 2 cases with CA and (in 1 case) worsening renal function, and in 2 controls because of ventricular tachycardia episodes and (in 1 case) hypotension. CA patients showed a trend toward increased daily urinary output (p = .078) and a significant decrease in body weight (p < .001), without significant changes in NT-proBNP (p = .497) and eGFR (p = .732). Both CA patients and controls displayed similar changes in urinary output, weight, and eGFR, but NT-proBNP decreased more significantly among controls (p < .001). No differences were noted in rehospitalization rates, but CA patients experienced higher mortality at 6 and 12 months (p = .003 and p = .001, respectively).
Conclusions: Levosimendan appears safe for CA patients needing inotropic support. The diuretic response and weight decrease during hospitalization were comparable between CA patients and matched HF patients, despite the greater mortality of CA patients after discharge.
Abstract
Topic: Prognosis ATTR
Background: Transthyretin cardiac amyloidosis (ATTR-CA) potentially affects the liver through amyloid deposition and systemic congestion from right ventricular (RV) dysfunction. The severity of liver disease may predict outcomes.
Methods: Liver function biomarkers measured at the time of diagnosis were evaluated in patients with ATTR-CA from 3 Italian centers. The endpoint was all-cause mortality.
Results: In a cohort of 460 patients (86% men, median age 81 years [interquartile range 76–85], 97% with wild-type disease), aspartate aminotransferase (AST) was 25 U/L (20–30, reference value [r.v.] < 35), alanine aminotransferase (ALT) 21 U/L (15–30, r.v. <56), gamma-glutamyltransferase (GGT), 47 IU/L (29–105, r.v. <38), total bilirubin 17.1 µmol/L (10.3–25.7, r.v. <20.5) and alkaline phosphatase (ALP) 77 IU/L (60–109, r.v. <147). Over 2.5 years (1.4–3.9), 175 (38%) patients died. GGT was the only independent predictor of for all-cause mortality in a model including age, National Amyloidosis Centre (NAC) score, left ventricular (LV) ejection fraction and mass index: hazard ratio for log2-transformed GGT, 1.17, 95% confidence interval 1.02–1.34, p = .025). The independent prognostic value was lost after adding tricuspid annular plane systolic function and systolic pulmonary artery pressure to the model (p = .082). At spline curve analysis, the risk of death increased with GGT levels, with a cut-off established at 46 U/L.
Conclusions: GGT elevation is particularly common in patients with ATTR-CA. The risk of mortality increases by 17% for each doubling of GGT irrespective of age, NAC score, LV systolic function and mass. This prognostic value can be explained, at least partially, by RV dysfunction driving liver congestion.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: The value of 99mTc-Pyrophosphate cardiac scintigraphy (PYP) for monitoring disease progression in transthyretin cardiomyopathy (ATTR-CM) patients still remains to be defined.
Methods: A retrospective analysis of sequential quantitative assessments of cardiac 99mTc-Pyrophosphate uptake that were correlated with echocardiographic evaluations over time. In PYP planar images we assessed the visual Perugini score and heart/contralateral (H/CL) radiotracer uptake ratio, and in SPECT images we computed a Cardiac Pyrophosphate Activity index (CPA) calculated from the mean uptake of the 99mTc-Pyrophosphate in left and right myocardium corrected by the blood pool activity.
Results: Five male patients were included, median follow-up of 3 years, age 75.8 ± 5.0 y.o., 2 wild-type and 3 hereditary patients (2 with p.Val50Met and 1 with p.Val142Ile mutations), on treatment with Tafamidis (n = 1) and Patisiran (n = 4). Between the initial and final evaluations, we observed a reduction of the Perugini score in 2 cases (from 3 to 2), reduction in the H/CL ratio in all cases (from 2.13 ± 0.1 to 1.57 ± 0.2, p = .0005 – paired Student T test), and reduction of the CPA in all cases (1010.8 ± 423.7 to 439.1 ± 326.9, p = .0439). Conversely, echocardiogram showed further increase of interventricular septal thickness in all patients (from 14.0 ± 2.5 mm to 17.0 ± 4.2 mm, p = .21).
Conclusions: In patients receiving anti-amyloid treatment, reduction of 99mTc-Pyrophosphate cardiac uptake is a common finding that may not correlate with other imaging markers assessing structural amyloid heart disease progression. Our results suggest that further investigation is warranted to define the role of PYP for monitoring ATTR-CM response to treatment.
Abstract
Topic: Diagnosis AL
A 47-year-old male was admitted to our inpatient clinic for scheduled electrical cardioversion of recurrent atrial fibrillation. He had no cardiovascular risk factors; the arrhythmia was an incidental finding. His only complaint was a mild decrease in exercise tolerance.
Because of ECG finding of low voltages and mild left ventricle hypertrophy in a previous echocardiogram in a young patient without history of untreated hypertension, a new echocardiogram was performed. This revealed moderate thickening of left ventricle with granular sparkling aspect of the myocardium consistent with the suspicion of cardiac amyloidosis.
The patient underwent a cardiac-MRI that supported the suspected diagnosis, with post-contrast inversion recovery sequences showing diffuse late-gadolinium enhancement in all cardiac chambers. The exam also showed a large mass at sternal manubrium, so that a whole-body CT scan was performed revealing diffuse osteolytic lesions in the skull, pelvis, shoulder blade and ribs in addition to the known sternal mass.
Laboratory exams showed severe proteinuria, significant hypergammaglobulinemia, and monoclonal free light chain in blood and urine samples. The patient subsequently underwent a bone marrow biopsy showing plasma cells infiltrate and green birefringence with polarized light microscopy.
A diagnosis of light chain amyloidosis with cardiac involvement secondary to micromolecular Multiple Myeloma was made.
The case highlights the importance of performing an accurate anamnesis and physical examination as well as careful examination of first level exams in patients presenting with a common condition that could hide a more complex clinical picture.
Abstract
Topic: Diagnosis ATTRv
Introduction: In Brazil, besides the wild-type (wt) form, the predominant mutation leading to hereditary transthyretin (ATTR) cardiomyopathy (ATTR-CM) is Val142Ile. We sought to compare the clinical presentation of patients with wt and Val142Ile mutation ATTR-CM in a Brazilian cohort of the Transthyretin Cardiac Amyloidosis Registry in State of São Paulo (REACT/SP).
Methods: Among the 642 patients enrolled in REACT/SP, 283 presented ATTR-CM, being 85 wt and 90 Val142Ile. We compared the main clinical characteristics between groups.
Results: The wt in comparison to the Val142Ile patients, presented, respectively: older age (78.4 ± 8.5 vs 74.2 ± 8.1 y.o., p = .0009); similar proportion of males (82% vs 81%, p = .85); lower proportion of blacks (11% vs 39%, p = .0001); similar prevalence of heart failure (HF) symptoms (85% vs 79%, p = .33); higher prevalence of syncope (13%vs2%, p = .008) and Pacemakers (PM) implantation (8% vs 1%, p = .027); similar prevalence of neuropathy manifestations (38% vs 51%, p = .17); lower creatinine (1.5 ± 0.8 vs 2.1 ± 2.1 mg/dL, p = .02) and NT-ProBNP levels (2860.0 ± 2843.3 vs 5488.3 ± 5455.6 pg/mL, p = .0001); reduced interventricular septal thickness (15.6=/-3.3 vs 17.0 ± 3.3 mm, p = .006), posterior left ventricular (LV) posterior wall thickness (14.2 ± 2.4 vs 16.2 ± 4.4 mm, p = .0003), higher LV ejection fraction (52.0 ± 10.1 vs 48.2 ± 13.6%, p = .038), higher global LV longitudinal strain (8.6 ± 8.7 vs 3.4 ± 9.8, p = .0003), smaller LV diastolic diameter (45.9 ± 6.1 vs 43.0 ± 7.3 mm, p = .005) at 2D-Echocardiogram.
Conclusions: In the Brazilian population wt and Val142Ile patients had similar clinical presentation regarding HF and neuropathy symptoms, but higher prevalence of syncope and PM in wt patients. Conversely, Val142Ile patients presented more severe amyloid cardiac infiltration.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Acquiring patient-reported outcomes (PROMs) such as health-related quality of life (HRQoL) is essential for monitoring and improving patient care in systemic amyloidosis. A patient-centered outcome assessment tool for AL amyloidosis has been recently developed using PROMIS and PRO-CTCAE measures. Our local Institute of Medical Informatics has developed an academically driven, open-source Electronic Data Capture (EDC) tool with electronic health record (EHR) integration. Using this tool and the recently validated instruments, we collect HRQoL data from AL amyloidosis patients at our center, both prospectively and longitudinally in the context of routine clinical care, beyond the confines of clinical trials. This approach aims to eliminate redundant data acquisition and is expected to ensure continuous and comprehensive data gathering in a real-world setting.
Our infrastructure supports collaborative research efforts through a federated study database, utilizing the established portal of medical data models as a central repository. The modular nature of our system allows for easy adaptation and expansion, including the incorporation of ATTR amyloidosis patients after validating PROMs in this cohort. Due to its interoperability, our EDC tool can be integrated in various EHR systems and data analysis pipelines.
The international amyloidosis research community is invited to collaborate and utilize this state-of-the-art infrastructure. The goal is to establish a federated, multi-center, multi-disciplinary, and international database of patient-reported outcome measures (PROMs) in systemic amyloidosis. This effort aligns with the FAIR principles and enables a comprehensive understanding of the disease's impact on quality of life, guiding future therapeutic interventions.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Early and accurate detection of cardiac amyloidosis (CA) is critical. Novel therapies for ATTR amyloidosis are less effective in late-stage disease, and patients often spend many years seeking an accurate diagnosis. We recently developed a novel technetium-99m labeled variant of the pan-amyloid reactive peptide p5 + 14 that may prove useful in the community cardiology setting as a facile, early screen for CA. Here we present data from the first-in-human study (NCT05951816) on the use of 99mTc-p5 + 14.
Methods: In this Phase 1, single-center, open-label study, a total of 35 subjects will be recruited – five (n = 5) healthy volunteers and 30 (n = 30) recently diagnosed patients with AL or ATTR amyloidosis. Subjects were administered ≤22 mCi of 99mTc-p5 + 14 intravenously and, at 1 h and 3 h post-injection, were imaged using planar scintigraphy and SPECT/CT imaging. Standard 99mTc-pyrophosphate imaging was performed on most patients at 72 h after 99mTc-p5 + 14 imaging.
Results: The planar and SPECT/CT images were of high quality and readily interpretable at both 1 h and 3 h post-injection. No cardiac uptake was observed in healthy subjects. In contrast, patients with CA had significant uptake of 99mTc-p5 + 14 in the heart evidenced in planar and SPECT/CT images (Figure 1). Preliminary assessment of the myocardium-to-blood ratio at 1 h post injection in patients was approximately 3:1. Pulmonary lesions were also 99mTc-p5 + 14 avid.
Conclusion: 99mTc-p5 + 14 is a promising new reagent for the facile detection of ATTR and AL CA using gamma imaging and may serve as a useful tool for the early detection of amyloidosis by community cardiologists.
Abstract
Topic: Basic Science AL
Background: Cell-mediated clearance of amyloid deposits is the most promising method for reversing pathology and improving organ function. Several opsonizing antibodies have been generated for AL or ATTR amyloidosis. However, in addition ot AL and ATTR, a pan-amyloid-reactive antibody could benefit patients with rare types of amyloidosis for which no treatments are being developed. AT-02 is a humanized IgG1 fusion protein incorporating two amyloid-reactive peptides. Here we further characterize AT-02 in support of its clinical evaluation as an immunotherapeutic for systemic amyloidosis.
Methods: The reactivity of AT-02 was characterized using ELISA. Amyloid targeting in vivo was assessed using the human AL amyloidoma mouse model and monitored by optical imaging. The stability of AT-02 in human serum was evaluated using a heparin-binding bioactivity assay. Lastly, AT-02 activity was tested in an rVl6WIL fibril elongation assay.
Results: The binding of AT-02 to amyloid in vitro is governed exclusively by the pan-amyloid peptide moieties. When injected into mice bearing a 20 mg human AL amyloidoma, AT-02 accumulated rapidly in the amyloid mass and remained visible in the lesion for at least 7 days post-injection (Figure 1). AT-02 was found capable of inhibiting rVl6WIL fibril elongation in a dose-dependent manner, and the peptides retained bioactivity for at least 9 days when exposed to human serum at 37 °C.
Conclusion: AT-02 is a novel pan-amyloid reactive antibody capable of rapid amyloid targeting and prolonged retention in vivo. It has good serum stability characteristics and can inhibit fibril elongation, further supporting its clinical evaluation in patients.
Abstract
Topic: Basic Science AL
Background: A family of pan-amyloid reactive peptides have been developed that bind amyloid through electrostatic pattern recognition interactions. These peptides can be used as carriers for delivering complex biological molecules to amyloid deposits in vivo. We have previously utilized a-helical peptides to target antibodies and Fc fragments to amyloid. Here we report the use of a beta-sheet peptide to generate a peptide-Fc fusion with amyloid reactivity and Ig-Fc functionality.
Methods: The peptide, p5sheet, was genetically fused to the C-terminal of a human IgG1 Fc domain. The Fc-p5sheet protein was produced transiently in HEK cells. The binding of Fc-p5sheet to amyloid extracts, synthetic fibrils, and heparin was assessed by ELISA. Ex vivo phagocytosis of fibrils and amyloid extracts was performed using activated THP-1 macrophages. Lastly, the biodistribution of 125I-Fcp5sheet was assessed in a murine model of AA amyloidosis.
Results: Purified Fcp5sheet fusion appeared as a single species by gel electrophoresis and chromatography. Fcp5sheet bound fibrils and extracts with Ec50 values of 0.8 nM-5.8 nM and specifically bound to cardiac AL and ATTR amyloid in tissue (Figure 1). Radiolabeled Fcp5sheet colocalized specifically with hepatosplenic amyloid when administered IV into mice with AA amyloidosis. The Fc domain remained bioactive in the context of the fusion reagent and induced phagocytosis of amyloid extract.
Conclusion: These studies further demonstrate that a class of polybasic peptides with various secondary structure can be used to target antibody-related molecules to amyloid deposits. This strategy is being used to develop pan-amyloid immunotherapeutics for amyloidosis.
Abstract
Topic: Diagnosis AL
76-year-old male patient with history of IgM lambda Waldenstrom macroglobulinemia (WM) and Large granular lymphocytic leukemia (LGL). He received multiple treatments for WM over 8 years. He achieved a partial remission and was kept under observation. He developed cytopenias secondary to LGL clone and was treated for that, ultimately becoming transfusion dependent. Due to worsening fatigue and recurrent ascites associated with elevated liver enzymes and worsening kidney function, he was admitted for further management. His baseline creatinine was 1.2 mg/dL, he presented 3 months later with creatinine of 1.74 mg/dL, urinalysis was bland and urine protein creatinine ratio was 0.43. Serum IgM 490 mg/dL, Serum lambda light chain 268 mg/L and serum Kappa light chain 14.3 mg/L. Kidney ultrasound showed no hydronephrosis. A kidney biopsy showed light chain (AL) amyloidosis involving glomeruli, vessels and tubulointerstitium. ECHO findings and elevated NT-Pro BNP were suggestive of cardiac amyloidosis. Given the expected findings of lymphoplasmacytic clone on prior bone marrow evaluation, he was started on Rituximab. His clinical picture and kidney function continued to worsen, and he was placed on hospice care.
WM and AL amyloidosis are rare disorders which uncommonly present concurrently. Treatment of AL amyloidosis in WM targets the lymphoplasmacytic clone identified on bone marrow biopsy and differs from plasma cell directed treatment such as daratumumab. Diagnosis needs high index of suspicion especially when the patient has mild proteinuria like our patient. Outcome is usually worse compared to non-IgM AL amyloidosis. Early detection might improve survival and preserve organ function.
Abstract
Topic: Diagnosis ATTRwt
Background: Cardiac amyloidosis (CA) involves abnormal amyloid protein deposition in organs, including the heart, causing restrictive cardiomyopathy. Atrial fibrillation (AF) prevalence in CA patients is higher than in age-matched populations. AF, the most common sustained arrhythmia globally, poses higher risks of stroke, cognitive impairment, myocardial infarction, sudden cardiac death, heart failure, chronic kidney disease, and peripheral artery disease. AF, poorly tolerated in CA due to restricted ventricular filling, shows a male preponderance. Limited data exists on gender differences in AF incidence among CA patients.
Methods: We conducted a single-center retrospective cohort study involving patients with ATTR-CA evaluated between 02/2016 and 12/2022. We compared patient demographics, comorbidities, and AF burden across genders.
Results: Our registry comprised 214 patients, with AF noted in 73% (n = 156) at diagnosis, significantly higher than the general population over 80 years (9%). Males constituted 91% (n = 195) and females 9% (n = 19). Despite a lower mean age of females (79.6 years vs. 81.2 years), there was no statistically significant difference in AF prevalence between genders after adjustment for co-morbidities, including age, race, CAD, prior CABG, COPD, DM, HTN, CKD (p value 0.21).
Conclusions: AF is the most common arrhythmia in general population, with a prevalence as high as 9% among individuals above the age of 80 years. Our data showed that the prevalence was much higher (73%) in patients with ATTR-CA. Although, males typically have higher prevalence of AF, our data indicates no statistical gender disparity, highlighting elevated risk among females with ATTR-CA.
Abstract
Topic: Basic Science AL
Introduction: Amyloid light chain (AL) amyloidosis is a protein conformational disease derived from the misfolded immunoglobulin light chain (LC). The great diversity of the LCs repertoire makes it difficult to identify the pathogenic LCs definitely. In this study, we identify the complete sequence of pathogenic LCs by combing RNA-based sequencing and mass spectrometry (MS).
Methods: 12 patients with biopsy-proven AL amyloidosis were included. Total RNA was extracted from bone marrow and for RNA-based sequencing. The pathogenic LCs were extracted from urine of the same patient by affinity chromatography, MS was applied to identify the repertoire and sequences of LCs, full length sequences of LCs were determined by combing RNA-based sequencing and MS analysis.
Results: Among these 12 patients with AL amyloidosis, serum, or urine immunofixation electrophoresis (IFE) detected clonal immunoglobulin in 10 patients, bone marrow flow cytometry detected abnormal plasma cell clone in 9 of 11 patients. By RNA-based sequencing, an IGVL dominant clonotype was identified in 11 patients, ranging from 20.4% to 94.7%. By MS analysis, VL dominant clonotype was determined in 7 patients, CL dominant clonotype was identified in all patients. The sequence coverage of VL and CL dominant clonotype detected by MS ranged from 12% to 47%, 91% to 100%, respectively. When combing RNA-based sequencing and MS analysis, the complete LCs dominant clonotype, along with the full-length sequences were determined in all patients.
Conclusion: RNA-based sequencing, combined with MS analysis can provide the full-length sequences and determined the pathogenic clonotype of LCs in AL patients.
Abstract
Topic: Diversity Equity Inclusion
Background: Transthyretin cardiac amyloidosis (ATTR-CA) is disproportionately diagnosed in older adult men; however, studies suggest that the true prevalence of ATTR-CA in women may be higher than previously reported.
Methods: The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study utilizes scintigraphy to identify ATTR-CA in self-identified Black/Caribbean Hispanic participants ≥60 years old with heart failure. We characterized the sex distribution and phenotypic characteristics of ATTR-CA in this active ascertainment cohort in comparison to a population of ATTR-CA patients who were referred to a tertiary care academic center.
Results: Compared to the referral clinic cohort, the active ascertainment cohort had a greater proportion of women (31.3% vs 13.3%, p = .016). This was mainly attributed to the higher proportion of women with wild-type disease [ATTRwt] (27.8% vs 7.1% females, p = .012), with no significant differences in proportion of women with ATTRv-CA due to Val122Ile. Women with ATTR-CA in the active ascertainment cohort exhibited higher left ventricular (LV) ejection fraction (61% vs 50%, p = .011); lower LV mass index (110 g/m2 vs 148 g/m2, p = .014); and lower posterior wall thickness (1.4 cm vs 1.6 cm, p = .01) than those in the referral cohort when indexed for body surface area.
Conclusion: An active ascertainment strategy for identification of ATTR-CA, as compared to a referral cohort, demonstrated a greater proportion of women with ATTRwt-CA and echocardiographic evidence of a less severe phenotype. Early identification of ATTR-CA in women is critical to reduce sex disparities in this clinically treatable disease.
Abstract
Topic: Diagnosis ATTRv
Background: Transthyretin (ATTR) amyloidosis is an increasingly prevalent condition. This report shares our experience diagnosing ATTRv amyloidosis.
Methods: ATTR amyloidosis was diagnosed based on a Perugini grade 2 or 3 positive pyrophosphate (PYP) scan, excluding light chain monoclonality. Genetic testing for TTR mutations followed ATTR amyloidosis diagnosis.
Results: Between July 2021 and November 2023, we identified 12 patients with ATTRv amyloidosis (ten men, two women), with an average age at diagnosis of 59 years (range: 45–75). All patients had a Perugini grade 3 positive PYP scan. Eight patients had the Thr60Ala mutation (Northern Iraq), one patient had Lys55Asn (Libya), another had Val142Ile (Sudan), and one had Ser43Asn (Iraq). (Table 1)
Clinical manifestations included symptoms of heart failure in nine patients, neurological manifestations in eight, diarrhea in six, and significant weight loss in 7. Symptom duration prior to diagnosis ranged from 4 months to 6 years. Electrocardiograms revealed low voltage in three patients, atrial fibrillation in two, QRS prolongation in six, with two requiring permanent pacemaker (PPM) implantation. All patients exhibited elevated natriuretic peptide and high-sensitivity cardiac troponin-I levels. Echocardiography revealed left ventricular hypertrophy in eleven patients, with pericardial effusion in seven. The left ventricular ejection fraction ranged from 28% to 69%. Genetic screening of 16 family members identified 12 mutation carriers. Two had further workup with ATTRv diagnosed in one.
Conclusions: This study provides valuable insights into the clinical profile and genetics of ATTRv amyloidosis in our region, underscoring the need for continued research and heightened awareness in amyloidosis.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Frailty is a multidimensional syndrome of decreased physiological reserve, characterised by a heightened vulnerability to stressors and has demonstrated prognostic significance across several cardiovascular conditions such as transthyretin amyloid cardiomyopathy (ATTR-CM). Our aim was to assess the prevalence of frailty and the association with disease severity in patients with ATTR-CM.
Methods: The Clinical Frailty Scale (CFS) is a clinical judgement-based tool which evaluates specific domains including comorbidity, function, and cognition to generate a frailty score ranging from 1 (very fit) to 9 (terminally ill). The CFS was used to retrospectively assess frailty in consecutive patients diagnosed with ATTR-CM at the St Vincent’s Amyloidosis Centre Sydney. Frailty was defined as a CFS ≥5. In addition, markers of disease severity were obtained.
Results: Seventy patients (62M:8F; age, median 79 years, interquartile range 10) underwent frailty assessment. Frailty was confirmed in 34/70 (48%) and was associated with increased interventricular septal diameter (p = .008), Gilmore Stage (p = .05) and New York Heart Association functional classification (NYHA) (p < .001). There was no association between frailty and age, gender, or renal impairment.
Conclusions: Frailty is prevalent among patients with ATTR-CM. It is associated with markers of advanced disease including NYHA and Gilmore stage. Frailty screening in ATTR-CM has the potential to enhance risk stratification and improve selection criteria for novel disease-modifying therapies.
Table 1 Baseline demographics and prognostic markers stratified by Clinical Frailty Scale dichotomous score.
Abstract
Topic: Treatments of AL
Background: Systemic light chain amyloidosis (AL Amyloidosis) is characterized by the aberrant clonal proliferation and deposition of insoluble amyloid fibrils within the extracellular matrix across various organs. AL amyloidosis in low- and middle-income countries (LMIC) is underdiagnosed primarily due to insufficient training and a dearth of multidisciplinary collaboration. Moreover, clinical outcomes are adversely impacted by delays in diagnosis and therapy.
Methodology: This study analyses patient characteristics and outcomes from the Amrita Amyloid Cohort. Patients were recruited between 2005 and 2023 in the Amrita Amyloid Centre, India’s first amyloid center. We use multiple imputations by chain equations to estimate quartiles for continuous characteristics and percentages with 95% CI for categorical characteristics.
Results: A total of 174 patients were included with a median age of 61 years and 77.9% were male. Patient characteristics and outcomes are shown in the Table. The most common mode of presentation was heart failure (64%). CyborD (Cyclophosphamide/ Bortezomib/Dexamethasone) was the most common induction regimen (57%). Advanced therapeutic options such as autologous stem cell transplant and CyborD/Daratumumab combination were used in 7 and 4 patients, respectively.
Conclusion: This study delineates the clinical course of AL amyloidosis patients in an LMIC setting. Given the lower survival rates compared to high-income countries, the findings underscore a need to improve detection and access to contemporary therapeutics in a resource-limited setting. Adequate training in identifying red flags from low-cost diagnostic methods such as ECG and echo has the potential to detect cardiac involvement thus paving the way for therapy optimization.
Abstract
Topic: Prognosis AL
Background: The prognosis of patients with AL amyloidosis is largely determined by the extent of cardiac involvement. The Revised Mayo 2012 prognostic model relies on biomarkers of cardiac injury and abnormal clonal plasma cell proportions. ECG and Echo parameters reflecting the extent of cardiac involvement might provide additional prognostic information.
Methods: We aimed to develop an ECG-Echo staging for AL amyloidosis using the Amrita Amyloid Cohort, the largest of its kind from South Asia. Sparse Principal Component Analysis was used to select three linear combinations of the potential ECG and Echo predictors. A risk score was developed from these predictor combinations using a Cox proportion hazard model with restricted cubic spline terms. This model was subsequently approximated by a decision tree pruned so that its R2 score would be at least 90%.
Results: A total of 174 patients were included in the study with a median follow-up time of 7 months. The following three combinations of risk factors explain 85% of the variability: average of septal S’ and lateral S’, RWT/SaVR, and EF. The decision tree is shown in the figure with survival curves. A bootstrap estimate of the Somers D from the ECG-Echo stages was 37%, a slightly better performance than the Mayo stages of 35%.
Conclusion: The ECG-Echo risk score provides relevant information about cardiac involvement in AL amyloidosis patients. This staging system might augment the Mayo risk classification. Further validation in a larger cohort is required to evaluate the added value of this ECG-echo staging.
Abstract
Topic: Prognosis AL
Background: Cardiac biomarkers are the strongest prognosticators in AL; inclusion of dFLC added granularity but these tools were developed in a different era.
Aim: To evaluate Mayo 2004 and Mayo 2012 in the recent era.
Methods: We analyzed 417 AL patients with data available for both Mayo 2004 (European modification to include stage-3B) and Mayo 2012.
Results: Per Mayo 2004, 60 (14%), 187 (45%), 81 (19%) and 89 (21%) were stage-1/-2/-3A/-3B and per Mayo 2012, 79 (19%), 88 (21%), 122 (29%), 128 (31%) patients were -I/-II/-III/-IV. Among Mayo 2012 stage-IV, 16 (12%) were Mayo 2004 stage-2, 46 (36%) -3A and 66 (52%) -3B. Primary therapy was bortezomib-based in 331 (79%) and daratumumab-containing in 95 (23%); 171 (41%) patients received daratumumab at any line. Five-year OS for stages-1, -2, -3A, -3B was 84%, 48%, 42% and 13%, with no significant difference for stages-2 and -3A (p = .176), and for stages-I, -II, -III and -IV was 77%, 59%, 33% and 30%, with no significant difference between stages-III and -IV(p = .150). First-line daratumumab improved outcomes across Mayo 2004 stage -2 and -3A and Mayo 2012 stage -I, -II and -III. Use of daratumumab at any line of therapy improved OS across all Mayo 2012 stages and among Mayo 2004 stages -2, -3A and -3B. Mayo 2004 and Mayo 2012 performed similarly (AUCs:0.656 and 0.618, respectively), however, Mayo 2004 stage-3B identifies a group of extremely poor prognosis, even among Mayo 2012-IV, independently of use of daratumumab.
Conclusion: cardiac dysfunction drives prognosis, but new therapies blurred the boundaries among stages in both Mayo 2004 and 2012. Clinical trial design should account for the impact of new therapies.
Abstract
Topic: Basic Science AL
MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by silencing messenger RNA (mRNA) targets. Identification of miRNA-mRNA interactions may provide valuable insights into the underlying molecular mechanisms involved in AL amyloidosis, paving the way for novel therapeutic approaches.
We profiled miRNAs and mRNA expression by RNA-sequencing and validated the sequencing by qRT-PCR in AL (n > 40), MM (n > 40) and Healthy controls (n = 10) CD138+ BM samples. In AL patients, miRNAs molecules were involved in regulating biological pathways such as mitochondrial energy-related pathways, MAPK, PI3K-AKT, Fatty acid metabolism and NFkB (Figure 1A).
miRNAs-9, 181a, 296, 331 and 4286, regulating the MAPK-ERK cascade, were downregulated in AL patients BM samples compared to MM/healthy controls (Figure 1A). Concurrently, we found that the protein levels of pERK, the main driver of this pathway, exhibited upregulation in AL BM samples, along with increased expression of its target genes, DUSP6, SPRY2 and COX-2. Treatment of primary cultures derived from AL-sorted CD138+ BM samples with MEK inhibitor (cobimetinib) revealed a marked inhibition of pERK expression (Figure 1B), its target genes and reduced cell viability. A set of miRNAs regulating the tumor suppressor PTEN exhibited upregulation in AL BM samples. PTEN, the key regulator of the PI3K pathway, showed downregulation, leading to activation of the PI3K pathway. Treatment with the PI3K inhibitor idelalisib reduced pAKT levels, cell viability and inhibited light chain secretion.
These findings reveal novel, non-DNA mutation-related mechanisms in AL amyloidosis mediated by miRNAs, which may assist in tailoring more specific treatments, using FDA-approved drugs.
Abstract
Topic: Basic Science ATTR
Cardiac AL and ATTR are potentially fatal cardiomyopathies. Current therapies do not address mechanisms of tissue dysfunction, mostly because these remain unknown. Our prior work has focused on the amyloid plaque proteome, which may not capture tissue-wide proteomic alterations. In this study, we used a whole biopsy proteomics approach to evaluate mechanisms of tissue dysfunction in cardiac AL/ATTR. We included 76 ATTR cases and 27 AL cases. In stage 3 AL patients, pathways involved in coagulation, extracellular matrix remodeling (ECM-R), epithelial-to-mesenchymal transition (EMT), complement activation, hypoxia and clathrin-mediated endocytosis were increased compared to stage 1/2, whereas pathways involved in healthy cardiac metabolism and proteostasis were decreased. In Mayo stage 2/3 ATTR, immunoglobulin proteins, complement and keratin pathways were increased compared to stage 1. Principal component analyses identified an ATTR group with worse survival independent of existing staging systems that also showed upregulation of complement and downregulation of oxidative phosphorylation pathways. Finally, when comparing AL with ATTR, complement proteins were increased in ATTR whereas clathrin-mediated endocytosis, mRNA splicing, spliceosome pathways and ribosomal proteins were increased in AL. Clathrin-mediated endocytosis has been implicated in Aβ amyloid clearance by non-immune cells in the setting of Alzheimer’s disease and could represent a proteostatic mechanism of cardiomyocytes in response to AL fibrils. Impaired spliceosome and translation machinery has been associated with cardiac ECM-R in other cardiomyopathies. Our results support an immune-mediated mechanism of tissue toxicity in cardiac amyloidosis including activation of the complement cascade, especially among ATTR patients with worse outcomes.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Background: Early detection and treatment of cardiac amyloidosis (CA) is critical to improving patient outcomes. We published an algorithm to detect cardiac amyloidosis using an artificial-intelligence (AI) enhanced analysis of the 12-lead ECG. Despite excellent performance characteristics, any predictive model for rare diseases will be fraught with false positives; therefore, additional predictive modeling for CA including blood, echocardiogram are layered onto the AI ECG score, comprising the A3E score.
Goal: To evaluate the use of the AI ECG and A3E scores in routine practice versus standard care in terms of more CA diagnoses and of provider satisfaction.
Methods: We implemented a randomized pragmatic trial in which providers – mostly cardiologists – were randomized to either an intervention arm or an observation arm. Interventional arm participants are notified of positive ECGs and provided with an order set to use (if appropriate) for additional amyloid tests and provided with other amyloid resources. The observation arm has access to tools but receives no notifications. Data are collected on all patients.
Results: As of 31 January 2024, 99 providers have been enrolled and randomized, and 12,370 distinct patients’ ECGs have been interrogated. By AI-ECG-score-alone, 1961 ECGs have been positive, but by layering other models on this score, only 294 of these were ultimately called positive. The PPV of the A3E score is 34.0% and the NPV is 99.4%.
Conclusion: The trial is ongoing but is providing insight into the feasibility and utility of incorporating AI models into clinical practice and support the feasibility for a larger study.
Abstract
Topic: Diversity Equity Inclusion
Introduction: Health disparities amongst ethnic groups are well documented in myeloma. NT-proBNP levels are 40% lower in Afro-Caribbean vs. Caucasians, with worse outcomes in heart failure. Little is, however, reported on ethnicity in AL amyloidosis. We compared disease characteristics and outcomes of patients across ethnic groups from the UK National Amyloidosis Centre.
Methods: Patients enrolled in a prospective observational study at the UK National Amyloidosis Centre treated from 2010–2019 were analysed.
Results: Of 1302 patients, 1265 had documented self-reported ethnicity: 1168 (92%) were White and 97 (8%) minority: 55 Black, 24 Asian, 13 Other, 5 Mixed. Baseline characteristics are shown (). Patients from an ethnic minority presented at a younger age (59 vs 67 years, p < .001). Pattern of organ involvement was similar (median:2 organs), however those from an ethnic minority had a lower presenting NT-proBNP (799 v 1577 ng/L, p < .001), with non-significantly lower troponin (39 v 55 ng/L, p = .15). Although a greater proportion of ethnic patients had severe heart failure symptoms (NYHA IV 2% v 0%), LV septal measurement (p = .61), longitudinal strain (p = .88) and dFLC (p = .79) were similar compared with white patients. Overall survival (OS) did not differ amongst any ethnic group; achieving an NTproBNP <1000 mg/L for survivors at 6 months predicted better OS similarly for white and minority groups.
Table 1. Presenting features of systemic AL by ethnicity.
Conclusion: Non-white ethnic groups present with AL at a younger age with a significantly lower NT-proBNP despite GLS% raising concerns about utility of staging systems and underestimation of disease risks. Further analysis of across ethnicities with larger patient cohorts is required.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Nuclear imaging can provide a non-invasive method for early detection and quantification of the amyloid. Technetium-99m (99mTc)-based bone tracers are already widely used in the diagnosis of transthyretin amyloidosis (ATTR). 99mTc-based radiotracers have significant advantages, wide availability, and low cost.
Aims: We aimed to develop 99mTc-based radiotracers for light chain amyloidosis (AL).
Methods: We evaluated the binding of three compounds-complexes, (benzothiazole and benzimidazole derivatives based on the thioflavin-T structure), in AL amyloid deposits. We generated AL amyloidoma-bearing mice by subcutaneously injecting Balb/c male mice between the scapulae with a solution of 80 mg amyloid fibrils from patient-derived light chains. The distribution of the 99mTc-complexes’ was evaluated with real-time imaging (γ-eye™, BIOEMTECH) and with biodistribution studies at 2, 30, or 90 min after intravenous administration of the radiotracer. Results: Dynamic imaging indicated that the 99mTc-1 and 99mTc-3 complexes are distributed within the amyloidoma, with no uptake at the site of injection. 99mTc-2 was not localized within the amyloidoma. The 99mTc-3 complex showed a rapid distribution from the blood to organs commonly affected by AL in 2 min. It was rapidly distributed within the amyloidoma and was not cleared at 30 and 90 min after administration. Importantly, 99mTc-3 was cleared from the heart at 30 min (while still present in the amyloidoma), suggesting that it is suitable for detection of cardiac AL at this timepoint.
Conclusions: We observed a differential binding of three compounds-complexes in the AL amyloidoma model. 99mTc-3 shows the best profile and is currently investigated for further development.
Abstract
Topic: Diagnosis ATTRv
Background: Amyloidosis is a challenging multisystem entity characterized by the deposition of amyloid fibrils in various organs, including the heart, nervous system, and gastrointestinal tract (GI), leading to a spectrum of clinical manifestations. Amyloidosis of the GI tract, with biopsy-proven disease, is rare. This case sheds light on the pivotal role of GI tract biopsy in initiating the diagnostic cascade, ultimately leading to the identification and comprehensive management of cardiac amyloidosis.
Case: An 87-year-old male with melena, 45-pound unintentional weight loss, and chronically elevated alkaline phosphatase underwent endoscopy and biopsy, revealing Congo red-positive staining in duodenal submucosal vessels (figure), confirming amyloidosis. Subtyping was hindered by limited tissue, prompting referral for cardiac evaluation. The patient exhibited atrial fibrillation, pseudoinfarct pattern on electrocardiogram, severe ventricular wall thickening on echocardiography, and chronically elevated cardiac biomarkers. Extracardiac manifestations included peripheral neuropathy, rotator cuff tear, and spinal stenosis. Normal kappa and lambda light chains and absence of monoclonal proteins in serum and urine were noted. A 99mTc-pyrophosphate scan confirmed diffuse myocardial uptake.
Figure: (a) Congo red-stained duodenal biopsy of small vessels. (b and c) Polarized light microscopy showing green birefringence of amyloid deposits in the vessels.
Decision Making: Genetic testing ruled out hereditary subtypes, leading to a diagnosis of wild-type ATTR amyloidosis. Tafamidis was initiated for management.
Conclusion: Gastrointestinal symptoms indicating ATTR amyloidosis are rare, emphasizing the importance of cardiac evaluation in extracardiac amyloidosis. GI symptoms can herald an unrecognized underlying amyloidogenic disease process. While screening methods exist for certain presentations, such as carpal tunnel syndrome, none currently exist for GI symptoms. Future studies may inform targeted screening strategies for amyloid in patients with identifiable GI symptoms ‘red flags’.
Abstract
Topic: Basic Science AL
Background: In light chain amyloidosis (AL), immunoglobulin light chains (LCs) have been associated with cardiotoxicity, playing a critical role in AL-related cardiac dysfunction. Elucidation of the cardiotoxicity mechanisms may lead to the identification of potential cardioprotective therapies.
Aims: We aimed to: (1) generate a murine model recapitulating LCs’ cardiotoxicity and (2) identify the cardiotoxicity mechanisms and candidate cardioprotective therapies.
Methods: We selected three cardiotoxic LCs from patients with AL amyloidosis and cardiac involvement and two isotype control LCs. C57BL6 mice (n = 5–7/group) were randomized as follows: (1) PBS (vehicle), (2) WT_kappa, (3) AL_kappa, (4) WT_lambda, (5) AL_lambda1 and (6) AL_lambda2, receiving the LCs (1 mg/mouse) or vehicle via intramyocardial injection (IMI). Echocardiography and blood sampling were performed weekly. The animals were sacrificed 4 weeks post-IMI for histology, electron microscopy and investigation of the cardiotoxicity mechanism. Primary murine cardiomyocytes were used to evaluate cardioprotective agents.
Results: AL-lambda, but not AL-kappa LCs, significantly reduced systolic function compared to the vehicle and isotype control groups. Circulating lactate dehydrogenase was significantly increased in AL groups. AL_kappa induced CHOP/Bax pathway and cardiomyocytes’ shrinkage, indicative of apoptosis. AL_lambda LCs increased Beclin-1 mediated autophagy, autophagosomes’ numbers, and cardiomyocyte size. Overexpression of endoplasmic reticulum stress (ERS) markers, IRE-1a and Bip, was observed in AL groups. None of the animals bared amyloid deposits. In vitro, treatment with the IRE-1a inhibitor, STF-083010, and tauroursodeoxycholic acid restored the LC-induced cardiotoxicity.
Conclusions: The IMI stands as a method to investigate LCs cardiotoxicity in vivo in the absence of amyloid deposits via which we identified ERS as a target to alleviate AL-LCs toxicity.
Abstract
Topic: Treatments of ATTR
Background: Cardiovascular hospitalization (CVH) is an indicator of higher mortality in patients with undifferentiated heart failure. Whether this association might be observed in the ATTR-CM population is unknown.
Methods: The phase 3 ATTRibute-CM trial of acoramidis – a novel, potent, near-complete transthyretin (TTR) stabilizer that increases serum TTR (prealbumin) – demonstrated improved clinical outcomes in ATTR-CM patients including a 50% reduction in the risk of CVH compared to placebo over 30 months, with a positive treatment effect observed as early as 3 months. From this trial, the relationship between those with or without CVH and survival was analyzed across treatment arms using the Kaplan-Meier method statistical approach.
Results: In ATTRibute-CM, the mean (± SD) age of the patients was 77 ± 6.6 years, 90.2% were men, and 90.3% had wild-type TTR. The baseline median (IQR) NT-proBNP was 2326 (1278–3910) pg/mL and mean (± SD) eGFR 61 ± 18 mL/min/1.73 m2. Those without any CVH had a 30-month survival of 86.7% (95% CI =82.9, 89.7) versus 60.1% (95% CI =52.8, 66.7) in those who had any CVH (p < .0001) as seen in the figure. Analysis is ongoing and additional results will be presented.
Conclusion: To our knowledge, this is the first time a prospective trial demonstrates that CVH portends a higher subsequent mortality in ATTR-CM patients. This suggests that effective treatment to reduce the need for CVH is critically important, and highly effective, targeted therapy for ATTR-CM that reduces CVH can improve the prognosis of patients with ATTR-CM.
Abstract
Topic: Prognosis AL
Introduction: Renal AL amyloidosis can be complicated by end-stage renal disease (ESRD) requiring renal replacement therapy (RRT). Renal staging based on 24-h proteinuria and estimated glomerular filtration rate (Palladini, 2014) predicts the risk of progression to ESRD. Herein, we evaluated the utility of renal staging among patients undergoing autologous stem cell transplantation (ASCT)
Methods: Retrospective chart review of patients (n = 697; Mayo Clinic, BU) with renal AL amyloidosis who underwent ASCT between 2003–2020. Renal stage was assigned at pre-ASCT timepoint. Patients who progressed to ESRD before ASCT were excluded. Renal survival was measured from the day of ASCT. Patients who did not progress to ESRD were censored, irrespective of life status.
Results: Pre-ASCT renal stage was I, II, and III in 35%, 52%, and 12% of patients, respectively. With a median follow-up of 10.4 years, RRT was initiated for 149 patients (21%). Pre-ASCT renal stage was significantly associated with renal survival: the 3-year RRT rate was 3%, 10%, and 37% for renal stage I, II, and III, respectively (Figure). The median time from ASCT to ESRD was 3.3 years. In multivariate analysis, renal survival was independently associated with the renal stage (hazard ratio [HR] 4.3 and 18.1 for stage II and III vs stage I, respectively); lambda isotype (HR 1.9); bone marrow plasma cell percentage ≥20% (HR 0.3); post-ASCT hematological response (higher HR with lower response); and ASCT era (HR 0.4 for 2012–2020 vs 2003–2011).
Conclusion: Renal stage reliably predicts renal outcomes in patients with AL undergoing ASCT.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by inexorable disease progression resulting in substantial cardiovascular morbidity and mortality. Acoramidis – a novel, potent, near-complete transthyretin (TTR) oral stabilizer that increases serum TTR (aka prealbumin) – is under development for the treatment of ATTR-CM. The phase 3 ATTRibute-CM trial of acoramidis was a randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of acoramidis in symptomatic ATTR-CM patients that met its primary hierarchical efficacy endpoint with mortality, morbidity, and function components (p < .0001). The trial demonstrated improved clinical outcomes in ATTR-CM patients including a 50% reduction in the risk of cardiovascular hospitalizations (CVHs) compared to placebo over 30 months.
Methods: We report a prespecified time-to-first-event analysis for the composite of cardiovascular mortality (CVM) or CVH, based on adjudicated data, using the Cox Proportional Hazards model.
Results: In ATTRibute-CM, the mean (± SD) age of the patients was 77 ± 6.6 years, 90.2% were men, and 90.3% had wild-type TTR. The composite of time to first event (CVM or CVH) was reported in 136/409 (33.3%) and 98/202 (48.5%) of acoramidis and placebo-treated patients, respectively, corresponding to a 15.2% absolute risk reduction, (number need to treat: 7), and a 38.2% hazard reduction (p = .0003). As shown in the figure, the Kaplan-Meier curves separate early, at month 3, and steadily diverge through month 30.
Conclusion: Acoramidis treatment resulted in an early and profound reduction in the composite endpoint of cardiovascular death or hospitalization in ATTR-CM patients.
Abstract
Topic: Treatments of ATTR
Background: The ATTRibute-CM trial demonstrated that acoramidis – a novel, potent, near-complete transthyretin (TTR) stabilizer – improves clinical outcomes in ATTR-CM. The association between change in serum TTR and first cardiovascular hospitalization (CVH) has not previously been described.
Methods: The association between change from baseline (CFB) to day 28 serum TTR levels and first CVH was analyzed with a multivariate stratified Cox proportional hazards model with baseline 6MWT and CFB in TTR level at day 28 as covariates, and was stratified by treatment group, baseline TTR < or ≥20 mg/dL, and randomization stratification factors of genotype (variant vs wild-type), NT-proBNP level (£ or >3000 pg/mL) and eGFR level (< or ³ 45 mL/min).
Results: For patients with day 28 CFB TTR values, LS mean (95% CI) CFB was 9.09 (8.65, 9.54) and −0.52 (−1.15, 0.12) mg/dL in the acoramidis and placebo arms, respectively (p < .0001); at month 30, LS mean (95% CI) CFB was 5.78 (5.01, 6.54) and −1.32 (−2.38, −0.26) mg/dL, respectively (p < .0001). Each 1 mg/dL TTR increase at day 28 post-therapeutic intervention was associated with a 4.7% lower risk of a first CVH over 30 months. These observations were independent of baseline TTR levels (Table).
Conclusion: To our knowledge, this is the first analysis from a prospective study of the relationship between CFB in TTR and subsequent risk of first CVH in ATTR-CM. We demonstrate that a greater increase in TTR is significantly associated with lower risk of CVH.
Abstract
Topic: Treatments of Other More Rare Amyloidoses
Background: Although the renal outcomes in light chain (AL) amyloidosis has been extensively studied, there is a paucity of data describing outcomes associated with clone-directed therapy for the various subtypes of non-AL monoclonal gammopathies of renal significance (MGRS).
Methods: This was a retrospective analysis of patients treated at two National Cancer Institute (NCI)-designated cancer centers in the United States. Patients were eligible if they had renal biopsy-confirmed histopathologic findings compatible with MGRS. AL amyloidosis was excluded. The primary outcome was renal survival, defined as time from diagnosis to renal replacement therapy (RRT) or renal transplant. Baseline characteristics, therapeutic strategy, and renal survival across the two most common MGRS subtypes: proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) and light chain deposition disease (LCDD).
Results: 65 patients were included; 23 (35%) ultimately required RRT or transplant. A clonal population thought to be causing MGRS was identified on bone marrow biopsy in a majority of LCDD patients (n = 20, 95%), while clones were infrequently found in PGNMID (n = 6, 23%). The vast majority (n = 20, 95%) of patients with LCDD received bortezomib-based therapy, whereas PGNMID therapy was more mixed (35% bortezomib, 38% rituximab, 23% other). Despite differences in therapy, patients with LCDD and PGNMID had similar risk of RRT (HR 0.83 (95% CI 0.52–1.33); p = .44) (Figure).
Conclusion: Patients with MGRS remain at high risk of requiring RRT even with clone-directed therapy. Despite differences in pathogenic clones and therapeutic strategies, outcomes of patients with PGNMID and LCDD are similar.
Abstract
Topic: Prognosis/Natural History Other More Rare Amyloidoses
Background: Monoclonal Immunoglobulin deposition disease (MIDD) is characterized by Non-amyloidogenic linear amorphous deposition of monoclonal immunoglobulin secreted by a clonal population of plasma cells within the basement membrane of glomeruli, tubules and blood vessels in kidneys. We investigated plasma cell cytogenetic abnormalities in MIDD.
Methods: This was a retrospective analysis of patients treated for MIDD at two National Cancer Institute (NCI)-designated institutions in the United States. The primary outcome was renal survival, defined as time from diagnosis of MIDD to requiring renal replacement therapy (RRT) or renal transplant, with patients censored at last follow up or death. Patients with multiple myeloma were excluded. Baseline characteristics and renal survival were compared for patients with and without t(11;14).
Results: Translocation (11:14) was identified in 12/27 (45%) patients. Among patients without the translocation, del13q and hyperdiploidy were the most common cytogenetic abnormalities. Compared to patients with MIDD without t(11;14), patients with t(11;14) had less proteinuria (median 644 v. 3397 mg/24H, p = .045), but otherwise similar baseline characteristics. VGPR or higher was seen in 58% of t(11:14), and 30% without t(11:14). With a median follow-up of 750 days, 30% (8/24) progressed to ESRD. Low eGFR at diagnosis (HR 0.93, p = .045) was related to progression to ESRD. Renal survival was better in t(11:14) as compared to non (11:14) group, although not statistically significant (HR 0.11, p = .06) (figure 1).
Conclusions: Translocation (11;14) is a common abnormality in MIDD, affecting initial presentation and outcomes. Improved therapeutic strategies to optimize renal survival, perhaps including BCL2-inhibitors, need to be explored.
Abstract
Topic: Diagnosis ATTRv
Currently, ATTRv requires diagnosis and clinical follow-up. Light chain Neurofilaments (NfL) are a diagnostic tool in pathologies with axonal damage, such as polyneuropathy. ATTRv can be followed by quantifying NfL, allowing detect changes earlier than in electrophysiological tests and before clinical symptoms are established. The prognosis and quality of life, thanks to new drugs that stop disease progression, have improved significantly quality of life, as long as it is started as soon as possible. Determining NfL in carriers and patients allows us to know if there is disease activity as earlier as possible. NfL measurement is not available in most Spanish hospitals.
CENTTINELLA program, which allows measure NfL levels, to be universalized to any Spanish hospital.
Determination of NfL for the diagnosis and follow-up of patients and carriers of ATTRv. Protocol for collecting samples and sending them to the reference hospital, with a response time of 15 days, facilitating clinical decisions. In the first 6 months of the program, 150 applications have been received from 12 different provinces in the country. NfL should be universalized for diagnosis and follow-up of ATTRv. We propose the creation of more programs that allow its use.
Based on our experience, we propose its use for monitoring carriers, detecting increases in NfL levels to initiate early treatment. Monitoring of patients undergoing treatment, drug change in the event of therapeutic failure. In patients with liver transplant clinically stable, demonstrate disease progression.
Include NfL levels in clinical guidelines to establish change from carriers to patients.
Abstract
Topic: Treatments of ATTR
Background: Lower serum TTR levels are associated with greater cardiovascular mortality (CVM) risk in ATTR-CM. This interpretation is from retrospective analyses and has not been supported prospectively.
Methods: Acoramidis – a novel, potent, near-complete TTR stabilizer that increases serum TTR (prealbumin) – improved clinical outcomes in ATTRibute-CM. The relationship between change from baseline (CFB) in Day 28 serum TTR levels and CVM was analyzed with a multivariate stratified Cox proportional hazards model with baseline 6MWT and CFB in TTR level at Day 28 as covariates, and was stratified by treatment group, baseline TTR < or ≥20 mg/dL, and randomization stratification factors of genotype (variant vs. wild-type), NT-proBNP level (≤ or >3000 pg/mL) and eGFR level (< or ≥45 mL/min).
Results: For subjects with Day 28 CFB TTR values, LS mean (95% CI) CFB was 9.09 (8.65, 9.54) and −0.52 (−1.15, 0.12) mg/dL in the acoramidis and placebo arms, respectively (p < .0001); at Month 30, LS mean (95% CI) CFB was 5.78 (5.01, 6.54) and −1.32 (−2.38, −0.26) mg/dL, respectively (p < .0001). Each 1 mg/dL CFB TTR increase at Day 28 post therapeutic intervention was associated with a 5.5% reduction in CVM risk over 30 months. These observations were independent of baseline TTR levels (Table).
Conclusion: To our knowledge, this is the first prospective demonstration of the relationship between CFB in TTR and subsequent risk of CVM in ATTR-CM. We demonstrate that a greater increase in TTR is significantly associated with lower risk of CVM.
Abstract
Topic: Basic Science AL
Background: Chimeric antigen receptor-macrophages have been generated that express the p5 pan-amyloid-reactive peptide to facilitate amyloid clearance. Cell-based therapies do not have targeting capabilities but accumulate in sites of inflammation. Amyloid is a non-inflammatory pathology; however, we have observed trafficking of macrophages to the kidney in a murine model of AA amyloidosis. Here, we describe the temporal changes in cytokine levels during the development of AA amyloidosis, that contribute to this phenomenon.
Methods: Cohorts of H2/IL-6 mice were administered AEF intravenously (n = 3/group). At time 0 and 1, 3, and 5 wk post-AEF serum and organ samples (kidney, liver, and spleen) were harvested. Cytokine levels were quantified by flow cytometry (Legendplex Kit). Tissues were fixed in formalin, sectioned, and stained with Congo red and H&E, and the macrophage markers Iba-1, and CD68.
Results: In the kidneys we observed a significant increase in pro-inflammatory cytokines [CXCL1 (p < .0001), CXCL10 (p < .0001), TNF-α (p < .0010), CCL2 (p < .0033)] between wk 1 and 3 post-AEF, concurrent with the progressive deposition of amyloid (Figure 1A). This also coincided with an increase in Iba-1-positive macrophages in the kidney over the initial 3 weeks post-AEF (Figure 1B). At wk 5 post-AEF renal cytokine levels were normal. No significant changes in organ-related cytokine production were seen in the liver or spleen.
Conclusion: Renal amyloid formation in the mouse resulted in a pro-inflammatory response leading to recruitment of monocytes. Consequently, amyloid reactive CARM may be beneficial in patients with renal amyloid, and potentially also cardiac disease when pro-inflammatory environs is established.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Iodine-124-evuzamitide, is a novel radiotracer for the detection of systemic amyloidosis by PET/CT imaging, which is an inherently quantitative modality. Therefore, this technique can be used to monitor progression and regression of organ-specific amyloid load. Here we report a single site, open label, repeat imaging study (NCT05968846) of nine AL (n = 9) and ten ATTR (n = 10) patients imaged 2.9 ± 0.9 years apart. Changes in organ-specific radiotracer uptake were quantified and analyzed.
Methods: Patients received 1 or 2 mCi 124I-evuzamitide with PET/CT imaging at 5 h post injection. A manual 2D region of interest (ROI) analysis of the heart was performed, and standard uptake value ratios (SUVRmean) calculated. Contemporaneous serum biomarkers including NTproBNP were collected at each imaging session. Correlation analyses were used to test for associations between variables.
Results: All patients with ATTR (n = 10) received stabilizer or silencer therapy between imaging, whereas seven of the nine (7/9) AL patients were untreated during this time. In the whole population (N = 19), there was a significant correlation between the change in cardiac SUVRmean (%) and the change in serum NTproBNP (%) (rS =0.57, p = .011). Eight (n = 8; 89%) AL patients and seven (n = 7, 70%) ATTR patients had a decrease in cardiac SUVR. Cardiac uptake of 124I-evuzamitide (N = 19) correlated significantly with contemporaneous serum NTproBNP (rp = .64, p = .0034).
Conclusion: 124I-evuzamitide uptake in the heart may be used to monitor changes in amyloid load (Figure 1). These pilot data indicate that changes in radiotracer uptake correlate with changes in serum NTproBNP, a validated biomarker predictive of survival in AL amyloidosis.
Abstract
Topic: Diagnosis ATTRwt
Background: Lumbar spinal stenosis (LSS) is one of several recently investigated conditions thought to precede the development of systemic amyloidosis. Studies have observed amyloid in the ligamentum flavum (LF) removed during laminectomy surgery, mostly typed as transthyretin (ATTR) amyloid. However, the prevalence of amyloid-positive specimens has varied greatly from 20–80%. Here we report observations from a screening assessment at the University of Tennessee Medical Center.
Methods: Subjects ≥35 y without history of amyloidosis consented to LF analysis. Tissues were manually stained with alkaline Congo red (CR) solution, and amyloid load was assessed on a scale of 0–4 by an experienced reviewer. Serial tissue sections with sufficient material for immunohistochemistry (IHC) were stained with TTR and apolipoprotein-A1 (APOA1) antibodies, and a subset was stained with biotinylated amyloid-binding peptide, p5 + 14.
Results: The LF of 97 males (n = 53) and females (mean age 64 y) was evaluated. Amyloid was detected in 88% (85/97), with half receiving a CR score =1 (Figure A). Of the evaluable specimens, IHC was TTR-positive in 86% (36/42) and APOA1-positive in 71% (30/42); remarkably, many showed discrete regions of both types. Biotinyl-p5 + 14 stained LF amyloid in 100% of evaluated specimens (n = 31; Figure B). A significant positive correlation between CR score and age was observed (rS =0.49; p < .001).
Conclusion: Amyloid in the LF is not uncommon. Studies of the relationship between LF amyloid load and systemic amyloidosis, potentially assessed by amyloid-specific nuclear imaging with p5 + 14, may help define those LSS patients truly at risk of developing systemic amyloidosis.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Nuclear imaging is a promising method for the early detection of systemic amyloidosis. Peptide p5 + 14 is capable of binding all types of amyloid and can accept many radionuclides for PET or SPECT imaging. Peptide p5 + 14 has been successfully radiolabeled with iodine-124 and technetium-99m and evaluated clinically. Fluorine-18 is the most widely used PET radionuclide. Here we describe synthesis of a fluorine-18-labeled p5 + 14 and initial characterization of the reagent.
Methods: The silicon-fluoride-acceptor isotopic exchange method was used to radiolabel peptide p5 + 14 with fluorine-18. After drying, F-18 (<51 mCi) was dissolved in DMSO before addition of peptide precursor. After purification of the product, radiochemical purity and stability were measured. Binding to amyloid extracts was assessed, and the biodistribution of 18F-p5 + 14 was evaluated in mice using PET/CT imaging and biodistribution.
Results: The synthesis yield was 45 ± 4%, and the product was radiochemically stable for >5 h. The binding of 18F-p5 + 14 to synthetic rVl6WIL amyloid-like fibrils was 96.2% with 87.2% binding to human AL amyloid extracts. In AA mice, accumulation of 18F-peptide was observed in the liver and spleen using PET imaging at 1 h post injection. The peptide was eliminated by hepatobiliary clearance with a prominent gall bladder seen in the images. No free F-18 was observed in bone.
Conclusion: Efficient radiofluorination of p5 + 14 can be achieved using isotopic exchange chemistry. The bioactivity of 18F-p5 + 14 mimics that of other pan amyloid probes labeled with I-124 or Tc-99m and offers another alternative for the specific detection of amyloid by PET/CT imaging.
Abstract
Topic: Prognosis AL
Limited research exists on AL amyloidosis cases in low and middle-income countries (LMIC). We retrospectively analyzed AL amyloidosis patients treated at a tertiary care center in North India from January 2010 to July 2022. All patients had confirmed AL amyloidosis through histopathological examination. Patients with concomitant multiple myeloma were excluded. We examined clinical presentation, investigations, and treatment details. Hematologic response criteria included complete response (CR), very good partial response (VGPR), and partial response (PR), while renal response involved a >30% reduction in 24-h proteinuria. We analyzed 59 patients with a median age at diagnosis of 56 years (range 38–78 years); 59.3% were males. The median symptom duration was 6 months (range 1–18 months). Common presentations included proteinuria and/or renal dysfunction (67.7%), congestive heart failure (28.8%), peripheral neuropathy (13.5%), purpura and skin involvement (10.1%), and bleeding manifestations (10.1%). Renal and cardiac involvement occurred in 77.9% and 50.8%, respectively. The majority (81.3%) exhibited the lambda monoclonal light chain type. Bortezomib-based therapy was received by most patients (84.7%), while 4 each underwent autologous stem cell transplantation and daratumumab-based combination therapy. Median follow-up was 28 months (range 1–96 months). Hematologic response occurred in 72.8%, with 54.2% achieving CR/VGPR. Renal response was observed in 40.6%. During follow-up, 54.2% of patients died, resulting in an overall survival (OS) of 45.7%. AL amyloidosis poses significant morbidity and mortality even at a tertiary care center in LMIC. Early diagnosis and prompt initiation of treatment with novel agents are crucial for improving outcomes.
Abstract
Topic: Treatments of AL
Background: The use of cyclophosphamide, bortezomib and dexamethasone (CyBorD) is widely accepted in the treatment of newly diagnosed AL amyloidosis (NDALA) and more recently, the advent of daratumumab-an anti CD38 monoclonal antibody- has revolutionized the treatment NDALA.
Objective: The primary objective of this study was to assess the impact of three different Bortezomib containing regimens (BCR) over clinical outcomes in the treatment of NDALA.
Material and methods: Patients with NDALA treated upfront at our Institution with BCR were identified.
Results: 100 consecutive patients with NDALA were treated with upfront BCR from 01/12 to 12/2023. From these, 49 were treated with CyBorD, 35 with CyBorMe and 16 with D-CyBorD. Clinical characteristics are seen in . After a median follow up of 52, 35 and 6 months, ORR was reported in 63%, 71% and 68% for the CyBorD, CyBorMe and D-CyBorD groups respectively. Organ responses were seen in 22 (40%), 17 (48%) and 12 (75%) patients in the CyBorD, CyBorMe and D-CyBorD groups, p = .03 (D-CyBorD vs CyBorMe and CyBorD). Cardiac and renal responses were seen in 15/35 (42%), 12/23 (52%) and 10/14 (71%) and 15/36 (41%), 11/25 (44%) and 8/15 (53%) for CyBorD, CyBorMe and D-CyBorD, respectively. (p = .01 and 0.1). No differences on overall survival and progression-free survival were observed.
Table 1 Clinical characteristics for patients with NDALA treated with BCR at the APC.
Summary and conclusion: We report here that D-CyBorD appears to be an efficacious treatment even with a very short follow up period. A clear trend towards better organ response is noted in the D-CyBorD group.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Iodine-124I-evuzamitide, is a novel radiotracer for the detection of systemic amyloidosis by PET/CT imaging. Semi-quantitative data on organ-specific amyloid load can be obtained from the images. The relationship between cardiac uptake of 124I-evuzamitide and echocardiographic parameters in patients with amyloid cardiomyopathy is of particular interest. We have evaluated the uptake of 124I-evuzamitide and contemporaneous echocardiographic parameters in nine AL (n = 9) and ten ATTR (n = 10) patients from the repeat imaging study (NCT05968846).
Methods: Patients received 1 or 2 mCi 124I-evuzamitide with PET/CT imaging at ∼5 h post injection. A manual 2D analysis of radiotracer uptake in the heart was performed by three reviewers. Whole organ cardiac uptake was assessed by automated segmentation (AIQ Solutions) and standard uptake value ratios (SUVRmean) were calculated. Contemporaneous transthoracic echocardiography was performed, and correlation analyses were used to test for associations between variables.
Results: The intraclass correlation coefficient for the three image reviewers was excellent (0.985, p < .001). In patients with AL amyloidosis (n = 9), the SUVRmean correlated strongly with LV thickness (rP =0.82, p = .0064) and GLS (%) (rP =0.73, p = .025), but not the IVS thickness (rP =0.56, p = .116). In patients with ATTR amyloidosis (n = 10), a moderate significant correlation between SUVRmean and LV thickness (p = .037), and IVS (p = .016) was observed (Figure 1). The correlation between manual and automated cardiac evaluations was highly significant (rP = .66, p = .0024, N = 19).
Conclusion: 124I-evuzamitide imaging is a promising technique for detecting cardiac amyloidosis. Cardiac amyoid load, based on PET imaging, correlated well with cardiac structure and function and may have prognostic value.
Abstract
Topic: Treatments of AL
Background: Advanced Cardiac amyloidosis remains an unmet need as patients struggle to tolerate anti plasma cell directed therapy and often present with severe heart failure that complicates therapy delivery due to increase toxicity.
Objective: The primary objective of this study was to describe the experience of the Amyloidosis program of Calgary on the treatment of newly diagnosed stage III AL amyloidosis (NDS3AL) as per the modified European Staging system.
Material and methods: Patients with NDS3AL were identified. Results: 70 consecutive patients with NDS3AL amyloidosis were treated with upfront Bortezomib Containing Regimens at the APC from 01/12 to 12/2023. From these, 17 patients were stage IIIB and 53 stage IIIA. Clinical characteristics are seen in . Median NTproBNP was 13,149 ng/L for the stage IIIB group compared to 3469 ng/L for stage IIIA. Hematological response was seen in 89% of stage IIIA patients compared to 58% in the stage IIIB group (p = .03). Cardiac response was seen in 54% of the stage IIIA patients compared to only 35% on the stage IIIB group (p = .09). At the time of analysis, 29 (54%) patients in the stage IIIA group and 12 (70%) in the stage IIIB group have progressed or died (p = .2). In addition, median survival was shorter for the stage IIIB Group (7 months compared to 52 months for the stage IIIa group (p = .03).
Table 1. Clinical characteristics for patients with NDALA treated with Bortezomib Containing Regimens at the Amyloidosis Program of Calgary.
Summary and conclusion: Stage IIIB patients had a shorter overall survival and high rate of early mortality. Novel strategies are needed for the management of this group.
Abstract
Topic: Diagnosis AL
Background: AL amyloidosis arises from accumulated light chains forming amyloid fibrils due to B-cell clone activity.
Objectives: In this study, we aimed to assess the role of a Monoclonal Gammopathy of Undetermined Significance (MGUS) clinic as potential group for the screening of amyloidosis.
Methods: Initially, we developed a biomarker driven screening based on fat pad aspirates and bone marrow biopsies for AL amyloidosis in cases with specific risk factors. Further, cardiac imaging studies were incorporated. Methods Retrospective chart reviews were completed for MGUS patients seen at the University of Calgary from 01/2013 to 01/2024. Those with abnormal free light chain ratios, amino terminal pro-brain natriuretic peptide (NTproBNP) > 300 ng/L, albuminuria, heart failure, and/or non-diabetic neuropathy underwent fat pad aspirate alongside routine monoclonal investigations.
Results: In total, 255 patients underwent fat pad aspirates. Three patients were diagnosed with AL amyloidosis after presentation, one case was diagnosed and typed via fat pad aspirate. Further, 5 patients progressed to AL amyloidosis at a median of 107 months, 1 case with localized AL amyloidosis to the lung and 4 with systemic progression. 12 other cases were diagnosed with ATTR amyloidosis via cardiac biopsy in 3, fat pad aspirate in 1, knee tissue in 1, bladder in 1, bone marrow in 1 and 4 via transverse carpal ligament biopsy, 2 other patients declined biopsy. All cases had a positive pyrophosphate scan consistent with ATTR.
Conclusion: The study highlights the feasibility of amyloid screening in a MGUS clinic. However, better, and more sensitive biomarkers are required.
Abstract
Topic: Diagnosis AL
Background: The diagnosis and management of amyloidosis requires coordination between multiple specialists to facilitate the diagnostic pathway for suspected cases.
Objectives: We reviewed the referral patterns to the cardiac and hematology amyloid clinics since the inception of the Amyloidosis Program of Calgary (APC) in 2019.
Methods: The APC is a multidisciplinary program that aims to facilitate the diagnosis and treatment of amyloidosis. A central referral system was created to expedite the evaluation of cases with potential amyloid related symptoms.
Results: The Cardiac Amyloidosis Clinic received 41 referrals in 2018 and the number of referrals increased up to 105 in 2022. During 2020 (COVID-19 pandemic), the number of referrals decreased from 67 in 2019 to 56 (Figure 1a). Most referrals came from general cardiology clinics, followed by hematology. 50% of the cases referred were ultimately diagnosed with ATTR and 18% with AL amyloidosis. The Amyloidosis Clinic at our Cancer Center was created in 2019. The number of AL amyloidosis cases remained stable with an increase from 16 to 25 new cases from 2018 to 2023 (Figure 1b)
Conclusion: We report here the impact of the formation of a dedicated multidisciplinary amyloidosis program in Calgary and the patterns of referrals from other services since its creation. An increase of ATTR referrals has been noted since the inception of the program, whereas the AL amyloidosis patients remain constant. The diagnosis of non-AL/ATTR cases have also increased as result of a more consistent typing protocol.
Abstract
Topic: Prognosis ATTR
Background: Wild-type cardiac transthyretin amyloidosis (wtATTR) is an age-related disease with adverse prognosis and increasing incidence. ATTR may adversely affect vascular function and accelerate vascular aging. Tafamidis, a TTR stabilizer, improves prognosis; however, whether tafamidis exerts any effect on vascular aging processes is unknown.
Methods: This is an observational, prospective study enrolling wtATTR patients receiving tafamidis. Patients were evaluated at baseline, 3, 6 and 12 months for markers of vascular aging including pulse wave velocity (PWV), and non-invasive pulse wave analysis. ATTR patients were compared to non-amyloidosis elderly controls (N = 30, age >70 years) who were assessed at baseline and 12 months.
Results: Twenty-one patients with wtATTR receiving tafamidis were recruited. PWV decreased compared to baseline, in patients receiving tafamidis [baseline vs a) 3 months: −0.95 m/s (95%CI −1.73, −0.159), b) 6 months: −1.36 m/s (95%CI −2.19, −0.54), c) 1 year: −1.08 m/s (95%CI −2.03, −0.12), p-Value < .01 for all]. Compared to controls, baseline PWV did not differ (12.48 m/s vs 12.21 m/s). However, in the control group PWV increased significantly after 1 year (mean change: 1.33 m/s, (95%CI 0.51, 2.15), p-value = .024), while PWV was significantly lower in wtATTR group after 1 year compared to the control group (p for interaction =0.0089). Central systolic blood pressure decreased after 6 months of treatment and returned to baseline levels after 1 year [6 months: −5.95 mmHg (95%CI −10.31, −1.60) p-value = .007, 1 year: −0.47 mmHg (95%CI −5.42, 4.49), p-value = .854].
Conclusion: Tafamidis may delay vascular aging in patients with wtATTR without affecting central hemodynamics
Abstract
Topic: Diagnosis AL
Background: The existence of patients with multiple myeloma (MM) and light-chain (AL) amyloidosis who present with a monoclonal gammopathy of undetermined significance (MGUS)-like phenotype has been recently reported with the aim of identifying a subgroup of patients with a better prognosis due to a more indolent course
Methods: An algorithm to identify patients having MGUS-like phenotype was used as reported recently on the basis of the percentages of total bone marrow (BM) plasma cells (PC) and of clonal PC within the BM PC compartment, determined at diagnosis using flow cytometry in 120 patients with AL amyloidosis treated with bortezomib containing regimens (BCR) from 01/2012 to 01/2023.
Results: Patients with AL amyloidosis and a MGUS-like phenotype had a better overall survival compared to patients with intermediate or Multiple Myeloma-like phenotype (Estimated of 119 months vs NR and 22 months, respectively, p = .001) (Figure 1a). Further, Progression-Free survival was longer in the MGUS like phenotype group of patients compared to the intermediate and MM-like groups (NR versus 34 and 13 months, respectively, p = .001) (Figure 1b). In a multivariate analysis, MGUS like phenotype, depth of response and less advanced staging correlated with better survival.
Summary and conclusion: We report here the role of MGUS-like phenotype for patients with AL amyloidosis treated with BCR at the Amyloidosis Program of Calgary. Our data validates the effect of MGUS like phenotype on survival in a consecutive treated group of AL amyloidosis cases.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Recently, a group of patients with a monoclonal protein that has no evidence of myeloma, lymphoma or amyloidosis was described as a new entity termed Monoclonal Gammopathy of Clinical Significance (MGCS) where patients exhibited clinical symptoms attributed to a B or plasma cell clonal expansion.
Objectives: We aimed to describe the frequency and clinical presentation of patients with MGCS evaluated at our Institution from 01/2014 to 01/2024.
Methods: Retrospective chart reviews were performed in all cases seen at our clinic and demographic variables were recorded. Results A total of 418 patients with MGUS were evaluated in the study period. 36 patients were referred with peripheral neuropathy, from those, 13 had an IgG kappa m-protein, 4 IgG lambda, 3 IgA kappa, 1 IgA lambda, 6 IgM kappa, 1 IgM lambda, 7 sFLC only and 1 with a HC and LC component. In addition, 15 patients had a Monoclonal gammopathy of Renal Significance (MGRS), 2 patients presented with DADS/M, 2 CIDP with MP. Other cases of MGCS included: NXG, Schnitzler’s syndrome, crystal keratopathy, Scleromyxedema, anti MAG syndrome, CANOMAD, among others. In total, 68 cases were diagnosed as MGCS. This represents 16% of cases. In addition, 2 MGCS patients had progressed to MM and 1 progressed from crystal keratopathy into MGRS.
Conclusion: MGCS is a new entity that is evolving in the past few years, clinical recognition and clonal directed therapy seemed the best way to improve clinical outcomes.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Recently, based on a prospective screening of 41,882 individuals and after 3.5 years of follow up, the IstopMM group reported new reference intervals for serum free light chains (sFLC) particularly for patients with preserved renal function. In addition, new sFLC reference values were defined based on age (<70 or >70).
Objectives: We aimed to describe the frequency of LC-MGUS based on the revised definition, as well as to assess clinical outcomes for patients deemed LC-MGUS with prior reference values.
Methods: Retrospective chart reviews were performed in all cases seen at our clinic and demographic variables were recorded. Results A total of 418 patients with MGUS were evaluated in the study period. From those, 63 (15%) cases were deemed to have LC-MGUS. On these cases, 29 (46%) had an eGFR >60 mL/min/1.73 m2, 16 (25%) (45–59 mL/min/1.73 m2), 7 (11%) (30–44 mL/min/1.73 m2) and 10 (15%) (<30 mL/min/1.73 m2). After the new revised criteria was applied, LC-MGUS was described in only 20 cases (4.8%), representing a relative decrease of 69% of cases previously considered LC-MGUS. After a median follow up of 70 months, 18 patients in the LC-MGUS as per new criteria and 60 as per the old criteria are alive. No patients with LC-MGUS defined as per old and new criteria have progressed to MM or AL amyloidosis.
Conclusion: Implementation of the new sFLC criteria defined as per the IstopMM group decreased the rate of false positive diagnosis of LC-MGUS, particularly for cases with preserved renal function (eGFR >60 mL/min/1.73 m2).
Figure 1. Overall survival (OS) for LC-MGUS based on IstopMM criteria. No differences in OS were noted (p = .7).
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Introduction: Transthyretin amyloidosis (ATTR) is a fatal disease caused by the misfolding of the protein, transthyretin (TTR). ATTR amyloidosis can be caused by genetic mutations (ATTRv) or age-related (ATTRwt). This study examined ATTR-related quality of life (QOL) among patients with ATTRv and ATTRwt.
Methods: The Amyloidosis Research Consortium (ARC) conducted a multi-country online survey of patients with ATTR amyloidosis in 2023. Survey measures included demographics, disease characteristics, and the Transthyretin Amyloidosis Quality of Life (ATTR-QOL). The ATTR-QOL measures the impact of ATTR on daily activities, social/role functioning, emotional wellbeing, and physical functioning, with higher scores indicating greater impact. Differences by genotype were evaluated with t-tests.
Results: Of the 309 ATTR respondents included in this analysis, the majority (n = 220 [71%]) had ATTRwt with 89 ATTRv patients, 37 of whom had Thr60Ala (T60A) TTR mutation, 34 had Val30Met (V30M) TTR mutation, and 18 had Val122Ile (V122I) TTR mutation. Mean (standard deviation [SD]) years since diagnosis were 4 (4) for ATTRwt, T60A ATTRv, and V122I ATTRv patients and 7 (6) for V30M ATTRv patients. V122I ATTRv patients had the highest mean ATTR-QOL impact score (44.7[24.7]); ATTRwt patients had the lowest (24.4 [20.1]) (Figure). Mean Daily Activities and Social/Role Functioning scores were higher among V1221 ATTRv patients (p < .05). While not statistically significant, Emotional Wellbeing and Physical Functioning scores were also highest among V122I ATTRv patients.
Figure 1. Mean ATTR – QOL impact scores by ATTR genotype.
Conclusions: ATTR amyloidosis has an impact on patients’ QOL. The results of this study suggest that disease burden differs across genotype, with the greatest impact among V122I ATTRv patients.
Abstract
Topic: Imaging
Subtopic: MRI
Background: Data on temporal progression of CMR parameters among light-chain cardiac amyloidosis patients (AL CA) are limited. We sought to investigate the impact of hematologic response on changes of CMR parameters in AL CA.
Methods: This study included consecutive patients from the National Center of Excellence in Amyloidosis who survived at least a year after the diagnosis of AL CA and underwent 3T CMR at diagnosis and 12 months of follow-up. Native T1, T2, myocardial and spleen extracellular volume (ECV) and peak left atrial strain (PALS). CMR parameters were compared among four levels of hematologic response.
Results: Our analysis comprised 79 AL CA patients (median age, 65 years; 56% male, median global longitudinal strain -15.9%, Mayo stage I = 12, II =28, III =33 patients). At baseline all patients had increased median native T1 (1410 ms), ECV (46.58), myocardial T2 (57.58), spleen ECV (46) and decreased PALS 11.74%. All CMR parameters increased significantly with increasing Mayo stage except PALS which decreased significantly. In the entire cohort a significant decrease in native T1 (from 1406 to 1396, p = .012) was detected at 12 months without differences in other parameters. Native T1 was markedly decreased among those with very good partial response (from 1418 to 1353 ms, p = .018) with numerical increase in those without response.
Conclusion: Although CMR parameters worsen with advancing disease severity, only native T1 changes significantly in response to treatment for AL CA.
Abstract
Topic: Prognosis/Natural History Other More Rare Amyloidoses
Introduction: Leukocyte Chemotactic Factor 2 (ALECT2) amyloidosis is the third most common renal amyloidosis and the second most common hepatic amyloidosis. ALECT2 amyloidosis is more prevalent among individuals of Hispanic, Native American, and Middle Eastern ancestry. Currently, no effective treatments are available for ALECT2 amyloidosis. This analysis examined the demographic and clinical characteristics of patients with ALECT2 amyloidosis participating in a multi-country survey study.
Methods: The Amyloidosis Research Consortium conducted an online cross-sectional survey of amyloidosis patients in the US, Germany, New Zealand, France, Italy, Spain, and Portugal in September 2023. Survey measures included demographic and clinical characteristics, including symptom severity.
Results: Of the 1031 survey respondents, 24 (2.3%) had ALECT2 amyloidosis and were included in this analysis. Two-thirds of patients (n = 16) were of Hispanic/Latino ancestry, 13 (54%) were female, and mean (Standard Deviation [SD]) age was 66 (7) years (). The mean (SD) time since diagnosis was 5 (4) years. The majority (96%) reported kidney involvement and 2 (8%) had liver involvement. One-third (n = 8) reported their current symptom severity as absent/mild, 11 (46%) had moderate symptoms, and 5 (21%) reported severe/very severe symptoms.
Table 1. Demographic and disease characteristics of leukocyte chemotactic factor 2 (Alect2) amyloidosis patients.
Conclusions: The demographics of surveyed patients with ALECT2 amyloidosis are described, and two-thirds of patients may experience moderate/severe symptoms. Further studies are needed to understand more about this patient population and address the unmet needs of ALECT2 amyloidosis patients.
Abstract
Topic: Treatments of ATTR
Background: Acoramidis is a novel, high-affinity stabilizer that achieves ≥90% transthyretin (TTR) stabilization. The phase 3 study, ATTRibute-CM, met its primary hierarchical efficacy endpoint with mortality, morbidity, and function components (p < .0001). Acoramidis treatment resulted in a 25% relative risk reduction (RRR) in all-cause mortality (ACM) and 30% RRR in cardiovascular mortality. We report results of acoramidis-mediated change in serum TTR, an in vivo measure of TTR stabilization, and its relationship to ACM.
Methods: Modeling and simulation analyses described acoramidis population pharmacokinetics. Exposure-response relationships were modeled for ACM versus serum TTR (prealbumin).
Results: Serum TTR levels on day 28 of dosing predicted survival in univariate analysis (Figure; p = .00161). A Kaplan-Meier plot of overall survival stratified by quartile of serum TTR change at day 28 showed significant differences by the log-rank test (p = .0055). In multivariate analysis, after adjusting for baseline demographic variables, diuretics, New York Heart Association functional classification, baseline serum TTR, TTR variant vs wild-type, and National Amyloidosis Centre stage, the change in serum TTR remained an independent predictor of ACM (p = .02257).
Conclusion: Statistical modeling demonstrates that acoramidis-mediated increase in serum TTR at day 28 is an independent predictor of survival.
Abstract
Topic: Prognosis ATTR
Background: Six-minute walk test (6MWT) is often used to assess functional capacity in a wide variety of cardiovascular conditions and is an important endpoint in trials of therapeutics for ATTR cardiomyopathy (ATTR-CM). However, 6MWT may be impacted by multiple factors including frailty. We therefore investigated the impact both of cardiac disease burden and frailty on 6MWT distance in patients with ATTR-CM.
Methods: 6MWT and other clinical data were prospectively collected in 98 ATTR-CM patients. Short Performance Physical Battery (SPPB) was measured to assess frailty. Statistical analysis was performed to evaluate the effect of age and disease burden (NTproBNP, global longitudinal LV strain (GLS), eGFR, diastolic function and NYHA class) and frailty (per SPBB score) on 6MWT distance.
Results: 93.9% of patients were male, median age 78.5 years (IQR 73, 83). The average 6MWT distance was 326 ± 107 m. On univariate analysis, age, SPPB score, eGFR, NT-proBNP, GLS, diastolic function and NYHA class were all associated with 6MWT distance. However, on multivariate analysis, the SPPB score remained the only independent predictor of 6 MWT distance (p < .001).
Conclusion: 1. Although cardiac dysfunction is a driver of 6MWT distance, baseline frailty is a more important factor. 2. Clinical trials that do not consider baseline frailty as a potential confounder in 6MWT distance may over- or underestimate the effect of a drug on cardiac function. 3. Thus, we recommend that future clinical trials of drug therapy stratify ATTR-CM patients by baseline frailty whenever utilizing the 6MWT as an endpoint.
Abstract
Topic: Basic Science ATTR
Transthyretin cardiac amyloidosis (ATTR-CM) is an often-underdiagnosed, progressive cardiomyopathy that can lead to heart failure and death. Gradual deposition of amyloid fibrils, consisting of transthyretin (TTR), within the myocardium causes cardiac thickening and dysfunction. Robust in vivo models are needed to elucidate the precise pathogenic mechanisms of ATTR-CM. We developed a murine TTR knockout model expressing the human V122I TTR variant. We observed increased human TTR levels in plasma compared to controls (110 ± 10 ng/mL vs. 28 ± 12 ng/mL; p = .0008) with preserved cardiac function (FS%: 20 ± 6 for ATTR vs. 23 ± 5 for control; p = .8162). Histopathological analyses revealed the amyloidogenic deposits within murine hearts, confirmed by Congo Red and Thioflavin T staining. Transmission electron microscopy confirmed immature and mature amyloid fibrils in ATTR (). Subsequent RNA-sequencing of the murine hearts unveiled distinct transcriptomic profiles similar to findings that we observed in human ATTR hearts, particularly highlighting inflammation-related pathways such as TNF, T-cell, and B-cell signaling. Up-regulation of inflammatory markers, including CXCL1/2/3 and CCL20, was also observed. Moreover, an increased level of CCL5 (MFI ATTR: 801 ± 105; Control: 426 ± 64; p = .0061, N = 3) was confirmed via luminance-based immunoassay. These chemokines are critical for directing leukocytes to inflammation sites. In summary, our humanized ATTR mouse model suggests a potential role for inflammation in the pathogenesis of ATTR amyloidosis. Further studies are needed to decipher the precise interactions between inflammation and ATTR-CM.
Figure 1. Transmission electron microscopy (TEM) shows immature (green arrows indicated dotted structures, magnification 25,000× and 40,000×) and mature (red arrows indicated thin, mesh-like, magnification 25,000× and 40,000×) amyloid fibrils in the cardiac extracellular matrix of ATTR mouse hearts compared to controls.
Abstract
Topic: Diagnosis AL
Introduction: Light chain amyloidosis (AL) is a rare, progressive, multisystem disease caused by a misfolding protein. Patients are benefitting from recent advances in treatment and increased disease awareness; however, their diagnostic journey is often lengthy and challenging. This analysis examined the diagnostic journey of patients recently diagnosed with AL amyloidosis in a cross-sectional study.
Methods: In 2022 and 2023, the Amyloidosis Research Consortium conducted online surveys of amyloidosis patients. Data collected included demographic, clinical characteristics, symptoms, and diagnostic journey. Recently diagnosed included patients diagnosed January 2021–May 2022 in the 2022 survey and patients diagnosed June 2022–November 2023 in the 2023 survey.
Results: Of the 2093 total respondents, 112 (5%) were recently diagnosed with AL amyloidosis (59 and 53 patients in the 2022 and 2023 surveys, respectively). Mean (Standard Deviation [SD]) time from symptom onset to AL amyloidosis diagnosis was 1.7 (4.1) and 1.7 (2.4) years in the 2022 cohort and 2023 cohort, respectively (). The heart and kidney were the most affected organs with 40 (68%) and 33 (62%) of patients reporting heart involvement and 32 (54%) and 34 (64%) reporting kidney involvement in the 2023 and 2023 surveys, respectively. More patients in the 2022 survey waited a month or more to start treatment (21 [38%]) compared to patients in the 2023 survey (12 [24%]).
Table 1 Patient demographic and clinical characteristics of patient with AL amyloidosis recently diagnosed by survey year.
Conclusion: These findings suggest patients are receiving treatment quicker after diagnosis of AL amyloidosis. Further studies are needed to evaluate if this trend is significant.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Monoclonal gammopathy of renal significance (MGRS) refers to renal disorders caused by a monoclonal immunoglobulin (MIg) including AL amyloidosis and other entities. The epidemiology of MGRS is largely unknown particularly in diverse populations.
Aim: To evaluate the epidemiology and clinical characteristics of patients with MGRS
Methods: We retrospectively analyzed all renal biopsies performed between 2009 and 2022 at Boston Medical Center (BMC), MA the largest safety net hospital in New England and evaluated the epidemiology and clinical characteristics of patients diagnosed with MGRS. Patients with multiple myeloma or those referred to the BMC amyloidosis center were excluded.
Results: 1898 patients underwent renal biopsies including 26% non-Hispanic Black (NHB)patients, 50% non-Hispanic white patients, 12% Hispanic and 7% Asian-Pacific patients. MGRS was diagnosed in 72 (3.8%) patients. Gender was similarly distributed between MGRS and non MGRS patients, but MGRS patients were older (mean age 65 vs 52, p < .05) and more frequently white (p = .0003). The most frequent type of MGRS (40%) was monoclonal immunoglobulin deposition disease (MIDD), followed by AL amyloidosis (29%) and PGNMID (10%). 78% of patients had detectable MIgin the serum or the urine. 22% had no detectable Mig, including 43% of patients with MIDD. 24-h proteinuria, creatinine, and age were variable among MGRS subtypes.
Conclusion: In this diverse population, patients with MGRS were more likely to be older and white. MIDD was the most frequent subtype of MGRS identified, and 43% those patients had no detectable MIg. Larger epidemiologic studies are needed to confirm these data.
Abstract
Topic: Diagnosis ATTRwt
It is known that valvular involvement by amyloid is frequently seen in the setting of aortic stenosis (AS). Amyloid derived from ApoAI (AApoAI) has long been known as an amyloid deposited locally in the aortic valve, but its relationship to AS is unclear. Since the high prevalence of concomitant severe AS and cardiac transthyretin-type amyloidosis (ATTR) has been reported, the prevalence of valvular involvement by ATTR and AApoAI has been examined. We analyzed amyloid proteins in 97 aortic valves removed for valve replacement for AS at Kyoto Prefectural University of Medicine between 2014 and 2021 using immunostaining and mass spectrometry. Amyloid deposits were found in 44 cases (45%), of which 30 cases (68%) were ATTR type and 33 cases (75%) AApoAI type. No significant association was identified between the presence of amyloid deposition and the results of various serological tests or echocardiography. Those results had no significant relation to percentage of areas with amyloid deposits in the total valve. Of patients with ATTR-positive aortic valves, none except one had a manifestation of ATTR cardiomyopathy. In this study, there were many cases with ATTR deposition in aortic valves but no systemic ATTR amyloidosis, those suggest the existence of localized valvular ATTR amyloidosis in the aortic valve.
Abstract
Topic: Pathology
Introduction: The gastrointestinal tract may be affected by deposits in the parenchyma and due changes in the autonomic nervous system. However, heart failure also may cause edema and hypoperfusion leading to an increased gut permeability and predisposes to intestinal microbiome disturbances.
Objective: the aim of this study was to identify the composition of the intestinal microbiome in patients with transthyretin amyloidosis with and without cardiac involvement and control group and correlate with echocardiographic parameters and cardiac biomarkers such as troponin and BNP.
Methods: 60 adults were included: 20 with cardiac involvement defined by a ventricular septum thickness >12 mm (G1), 20 without cardiac involvement (G2) and 20 controls (G3). The microbiome profile was obtained by sequencing the 16S rRNA gene (Illumina® Miseq).
Results: among the 40 patients (G1 and G2), 85% had the hereditary form and 15% the wild form. The most prevalent mutation was Val142Ile (52.9%), followed by Val50Met (17.6%). The differentially abundant bacterial genera in G1 and G2 were Streptococcus, Lachnospiraceae and Selimonas, while G3 presented a higher relative abundance of Metahanosphaera (Figure 1). Butyricoccaceae and Streptococcus were associated with higher levels of troponin I, while the genus Hungatela was associated with higher circulating levels of BNP (p < .05). Larger left atrial volumes were associated with Lachnospiraceae, and higher cardiac mass indexes were associated with Butyricoccaceae (p < .05).
Conclusions: patients with amyloidosis presented a particular intestinal microbiome profile when compared to control group and there was correlation with echocardiographic parameters and biomarkers of heart failure and necrosis.
Abstract
Topic: Prognosis AL
Background: Cardiac amyloidosis (CA) is a frequently underdiagnosed condition that carries a high fatality risk when left untreated or detected late.
Methods: We conducted an analysis of all patients diagnosed with CA at our institution between 1st January 2021 and 31st August 2023. Notably, specific therapy was unavailable for ATTR patients, whereas all AL amyloidosis patients received chemotherapy, while only one receiving immunotherapy. All-cause mortality was extracted from national census data and analyzed using Kaplan-Meier survival estimates and long-rank test. Due to the size of the sample, non-parametric statistical tests were applied.
Results: Nineteen patients were diagnosed with CA, with 13 (68.4%) presenting with amyloid light chain (AL) amyloidosis, and 6 (31.6%) with transthyretin amyloidosis (ATTR) (4 wild-type and 2 variant). The median age was 66 years, and 68% were male. The mean delay in diagnosis from initial medical consultation was 10.77 months, showing no statistically significant difference between AL amyloidosis and ATTR (p = .598 Mann-Whitney test), nor did it correlate with heightened mortality rates. Throughout a mean follow-up of 9.81 months, the median survival time was 10.56 months, with AL amyloidosis patients exhibiting the shortest survival (p = .001). Gender differences in mortality were not statistically significant (p = .387), and neither were global longitudinal strain (p = .128 Mann-Whitney test) nor left ventricular ejection fraction (p = .189 Mann-Whitney test) at the time of diagnosis.
Conclusions: AL amyloidosis patients had significantly lower survival rates during a short follow-up period, highlighting the urgent need for improved early detection and tailored treatments for the underserved population in the region.
Abstract
Topic: Basic Science AL
The mechanisms behind kidney damage in AL remain unclear, and unraveling those could lead to novel therapies.
Our prior work has demonstrated increased T cell subsets in the bone marrow of AL patients compared to other dysproteinemias.
We sought to characterize the immunome of renal AL and its correlation with clinical outcomes.
Using imaging mass cytometry, we explored the single-cell, spatial immune landscape of 45 renal AL biopsies. We included 17 control cases (10 nephrotic syndromes, 7 normal).
A total of 25,630 CD45+ cells were analyzed. B cells were lower in amyloid cases than controls (p < .001), which is likely secondary to systemic immunoparesis in AL. T-cells were increased in AL compared to disease/normal controls (16% vs. 2.3% vs. 1.9%, p < .001) and in AL renal stage 2/3 vs. 1 (18% vs 3.5%, p = .002). This was true for several cytotoxic T cell subsets, including HLA-DR + T cells, a highly activated subset (p = .003). Principal component (PC) analyses based on immune composition, identified two groups of patients (PC1 high and low). PC1-high patients had lower renal survival, an overrepresentation of several T cell subsets, antigen-presenting cells, and CD11c + positive B cells, a subset associated with autoimmune disease. Interestingly, T-cells and CD11c + B cells were spatially closer to glomeruli (p < .01 and <0.001, respectively) and further away from vessels than controls (p < .001 for both), which suggests active extravasation/chemotaxis towards glomeruli.
This work, along with other work presented in this meeting, supports the novel hypothesis of an immune-mediated tissue damage mechanism in AL.
Abstract
Topic: Diagnosis ATTRwt
Non-invasive diagnosis of ATTR cardiac amyloidosis (CA) can be established using bone scintigraphy (BS) according to consensus guidelines. We present a case series of patients who were misdiagnosed with ATTR-CA using the non-invasive pathway and were prescribed and/or treated with Tafamidis.
Twenty-six patients were identified from five referral centers. Eighteen (69.2%) were male and median age was 69 years. Twenty-five (96.1%) reported at least one symptom suggestive of CA (Table). Echocardiogram was performed in all, 18 (69.2%) had at least one feature suggestive of CA. Seven of the 12 (46.1%) who had cardiac magnetic resonance (CMR) performed had at least one feature suggestive of CA. Six (23.1%) did not have any feature suggestive of CA on echocardiogram or CMR. All patients had BS that was interpreted as positive in the initial institution. However, 19 (73.1%) of the previously reported positive BS were interpreted as negative at an amyloid referral center, two had an equivocal BS. Eight of 26 did not have SPECT performed with initial BS. Six patients were diagnosed with AL rather than ATTR, in these cases monoclonal protein studies performed at the initial institution were incomplete or misinterpreted.
Almost 25% of patients in this study were found to have AL, highlighting the potentially fatal nature of misdiagnosis using the non-invasive pathway. The remaining patients did not have a diagnosis of amyloidosis after evaluation at a referral center. This study highlights the perils of the non-invasive pathway of ATTR diagnosis if consensus guidelines are not followed.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
β2 microglobulin (β2 m) is responsible for systemic human systemic amyloidosis either due to persistently high concentrations of the wild-type (WT) protein in hemodialyzed patients, or in the presence of mutations, such as D76N β2 m, which favor protein deposition in the adulthood, despite normal plasma levels.
Numerous studies have been carried out in vitro characterize the mechanisms of β2 m amyloid conversion, however, many questions on the proteotoxicity in vivo are still open. Here we compare a Caenorhabditis elegans transgenic strain expressing human WT β2 m at high concentrations with the strain expressing the D76N β2 m variant at lower concentrations.
Both lines exhibit pathological phenotypes and show a significant remodeling of proteome and metabolome profiles, being more pronounced in the presence of higher levels of WT β2 m thus indicating that proteotoxicity correlates with β2 m levels rather than with the presence of mutations.
The β2 expression severely affects the nematode proteostasis inducing higher levels of molecular chaperones and other proteins involved in protein degradation. Redox imbalance and impairment in amino acids metabolism have also emerged. The joint proteomics and metabolomics pathway analysis highlights alterations in oxidative phosphorylation, fatty acids degradation and Krebs cycle, suggesting an impairment of the mitochondrial aerobic metabolism degradation and a shift to anaerobic metabolism.
Our studies confirm that the nematodes represent a good model suitable for studying the β2 m proteotoxicity in vivo. Most importantly, the ‘omics’ approaches provide insightful clues at the molecular level unveiling specific deranged pathways.
Abstract
Topic: Basic Science ATTR
Background: Cardiac amyloidosis is a myocardial storage disorder in which deposits of misfolded mono- or oligomers of the serum protein transthyretin (TTR) trigger a progressive amyloid cardiomyopathy (ATTR-CM). Naturally occurring autoantibodies (nAbs) are defined as germline-encoded autoreactive immunoglobulins found in individuals without (known) prior antigen exposure. A role of nAbs has been described in several neurodegenerative diseases. NAbs have not yet been described in cardiac storage diseases.
Objective: To identify nAbs in ATTR-CM and assess their role as biomarker in diagnosis and monitoring of disease progression and treatment as there is currently no established specific biomarker for ATTR-CM.
Material and methods: Serum from healthy donors as well as umbilical cord blood and pooled donor immunoglobins were tested for IgM and IgG antibodies against recombinant wild-type TTR, recombinant V122I-variant, recombinant L55P-variant and native TTR in fibrillar and non-fibrillar form by ELISA and dot-blot protein analysis.
Results: NAbs of the IgM type against TTR are already detectable in the umbilical cord blood. The titers differ from those of adult donors. There is no loss of detection in the fibrillar TTR form. The responsible B-cell fraction of TTR-specific IgM could be detected.
Summary and conclusion: NAbs of the IgM type against various TTR forms were detected. Their significance is currently unclear, thus underlining the importance of further investigations.
Abstract
Topic: Basic Science AL
Amyloid deposits in AL amyloidosis contain both the full-length monoclonal light chain (LC) and fragments encompassing its variable domain (VL) plus different length segments of the constant one (CL), thus highlighting the potential role of proteolysis in fibrillogenesis. Here we aimed to develop a biocompatible model of LC amyloidogenesis, accounting for the major species present in natural deposits.
Focusing on the amyloidogenic lambda LC AL55, we studied structure, molecular dynamics, stability, and amyloid-forming ability of a prototypic fragment containing both the VL and part of the CL (133AL55), in comparison with the fulllength protein (FLAL55) and to its variable domain (VLAL55). The three proteiforms were produced recombinantly. Fibrillogenesis kinetics, cross-seeding, aggregate structure, and molecular dynamics were assessed under biocompatible, non-denaturing conditions by biochemical techniques, electron microscopy, isotope-edited Fourier-transform infrared spectroscopy and high-resolution NMR.
In contrast to the full-length LC, which forms exclusively amorphous aggregates under shear stress, both fragments are amyloidogenic in vitro, but with different kinetics, structure of aggregates and interplay with the unfragmented protein. In particular, 133-AL55, with its dynamic truncated CL, under appropriate conditions entirely converts into amyloid fibrils microscopically and spectroscopically similar to their ex vivo counterpart. Although not incorporated into structured fibrils, amorphous aggregation of FLAL55 is increased by the presence of 133-AL55 fibrils.
These data can help us interpret the kinetics of amyloidogenesis in vivo and highlight how specific LC truncations influence amyloid onset and growth. This work raises the issue of the relation between truncated and full-length LC species, which needs further exploration.
Abstract
Topic: Diagnosis ATTRv
Introduction: The V122I founder appears to have originated in West Africa. The African ancestry is present all over Brazil, more prevalent in the northeast region. The aim of this study is to evaluate the distribution of V122I carriers in Brazil and determine its demographic characteristics.
Methods: A national, multicenter (10 reference centers), observational, cross-sectional study to evaluate the distribution and demographic characteristics among individuals with V122I mutation in Brazil.
Results: We found 246 TTR V122I carriers from 84 families: 240 heterozygous, 4 homozygous, and 2 compound heterozygous (V30M/V122I and I107V/V122I). Gender distribution was similar. Age: 19 to 89 years, mean 53.4. Race: 26.7% white, 17.3% black and 56% mixed. Individuals were born in all regions of Brazil, mainly in the states of Pernambuco (32.4%), Bahia (32%), São Paulo (16.4%) and Minas Gerais (8.6%). A greater concentration was found in the cities: Salvador (11%), Recife (8,9%) Uberlândia (4,5%) and in the banks of the São Francisco River. The distribution of state of residence maintained mainly in the same areas.
Discussion: This study demonstrates the V122I variant, both in whites, black and mixed Brazilian individuals and shows endemic areas with a high concentration of this allele on the northeast region of Brazil, which can be explained by a possible common founder effect. The slaves came to Brazil from 2 different regions: West and Central Africa. The endemic areas are associated with the slave route from West Africa. This study allowed a better understanding of the scenario of ATTRV122I Amyloidosis in Brazil.
Abstract
Topic: Pathology
Background: Clinical presentation of systemic amyloidosis differs among subtypes, and accurate subtype classification is important for choosing the treatment. ATTR amyloidosis was the predominant among the recently consulted amyloidosis cases in Japan.
Objective: To reveal the latest subtype frequency of systemic amyloidosis among autopsy cases in Japan.
Methods: We analyzed systemic amyloidosis cases autopsied from January 2017 to December 2018, that were listed in the Annuals of the Pathological Autopsy Cases in Japan, Volumes 60, 61. The Annuals are edited by the Japanese Society of Pathology and list all cases autopsied during the year at the hospitals registered in the Japanese Society of Pathology. When the subtype was unclear, we performed a questionnaire survey, immunohistochemistry with in-house rabbit polyclonal anti-κ116–133, anti-λ118–134, and anti-transthyretin 115–124 antibodies, and proteomic analysis (Figure).
Results: Out of 481 systemic amyloidosis cases listed in the Annuals, 411 cases were available for analysis (85.4%). We classified 399 of these systemic amyloidosis cases. ATTR was the most common subtype (44.4%, n = 177), followed by AL (38.8%, n = 155). AA and Aβ2M were 9.3% (n = 37) and 6.0% (n = 24), respectively. Double deposition of amyloid was identified in 1.6% (n = 6). In 168 cases (42.1%), systemic amyloidosis was the main cause of death. Of these cases, AL was the most common subtype (47.6%, n = 80), followed by ATTR (41.1%, n = 69).
Conclusion: ATTR is the most predominant subtype among the current autopsy cases in Japan.
Acknowledgements: We thank all the Japanese pathologists who participated in this study.
Abstract
Topic: Diversity Equity Inclusion
Background: Hereditary transthyretin (TTR) amyloidosis, a systemic disorder marked by the accumulation of transthyretin protein in organs, particularly the heart and nervous system, exhibits variant-specific severity. The V122 TTR variant, prevalent in African and Latin populations, correlates with heightened heart failure, while the V30M variant, common in Portuguese descent, including Brazilians, is linked to polyneuropathy. The S50A variant is common in distinct regions of Mexico. This study aims to assess the involvement of racial and ethnic minorities in TTR amyloidosis randomized control trials (RCTs).
Methods: PubMed was queried for RCTs treating TTR amyloidosis. Manuscripts, supplementary appendices, and ClinicalTrials.gov were examined for participant-level characteristics, intervention, and genetic variants of TTR.
Results: Nine RCTs were evaluated from 2013 to 2023 (), encompassing 1817 patients. Trials focused on pharmacologic interventions, with five targeting polyneuropathy and four addressing cardiomyopathies. The median trial size was 172 participants, averaging 66.8 years in patient age, with 21.3% women. Participation rates for V30M and V122I mutations were 22.8% and 15.7%, respectively. Non-Hispanic white (NHW) participation was 75.3%, Black participation was 13.2%, Hispanic participation was 7.9%, and Asian participation was 8.6%.
Table 1 Demographic and genetic characteristics across TTR amyloidosis randomized control trials.
Conclusion: Ethnic and racial minorities are underrepresented in TTR amyloidosis RCTs. The underrepresentation of racial and ethnic groups, particularly in trials addressing specific mutations prevalent in those populations, may impact the generalizability of study findings and the development of effective treatments for diverse patient populations. Addressing these disparities is crucial to ensure equitable access to novel therapies and enhance understanding of TTR amyloidosis across demographic groups.
Abstract
Topic: Treatments of ATTR
Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an infiltrative process with poor prognosis without treatment. Conduction system disease is prevalent among ATTR-CM patients. ATTR-CM patients are also predisposed to development of tachyarrhythmias such as atrial fibrillation, and less commonly ventricular arrhythmias. This project assessed the progression of conduction system disease and electrophysiological events in ATTR-CM patients, comparing those treated and untreated with tafamidis.
Methods: We collected baseline and serial longitudinal parameters associated with conduction system dysfunction and tachyarrhythmia in ATTR-CM. Comparison of the occurrence of study endpoints in treated and untreated patients was performed using paired analyses.
Results: A total of 145 patients with ATTR-CM (126, 87% men, 19 women; mean age at diagnosis 79.1 ± 0.7 years) were identified from 2011 to 2021. Eighty (55%) patients were treated with tafamidis. There were 102 (70%) patients with atrial fibrillation or flutter, and 42 (29%) patients underwent pacemaker or ICD implantation. The median baseline QRS duration increased significantly for both tafamidis-treated and untreated patients at 1-year follow-up compared to baseline. Tafamidis-treated patients had a baseline median QRS duration (Q1-Q3) of 104.0 ms (88.0–128.0 ms), which increased to 122.0 ms (96.0–166.0 ms) at 1-year follow-up (n = 45) (p < .05). Untreated patients exhibited a baseline median QRS duration of 119.0 ms (100.0–144.0 ms), which increased to 130.0 ms (106.0–160.0 ms) at 1-year follow-up (n = 30) (p < .05).
Conclusion: Tachyarrhythmia and conduction system disease, along with progressive QRS widening in follow-up, are highly prevalent in ATTR-CM, though similar between patients treated and untreated with tafamidis.
Abstract
Topic: Treatments of AL
Venetoclax (Ven), an oral BCL2 inhibitor, is a promising treatment option in patients with AL amyloidosis especially in plasma cell clones with t(11;14).
We report on the 3-year follow up data of 9 patients with relapsed/ refractory AL amyloidosis with t(11:14) and BCL2 expression treated with Ven.
8/9 patients had cardiac, and 5/9 patients had renal involvement. According to the revised Mayo risk model, 4/9 patients had stage IV disease, and 4/9 patients stage III disease, 1/9 had no troponin T measurement at baseline. All patients had BCL2 expression in >50% of the plasma cells, and all patients had t(11;14) by iFISH.
Patients had a median of two prior lines of therapy (range 1–4), including high-dose melphalan and autologous stem cell transplantation (2/9), daratumumab (9/9), bortezomib (6/9), and lenalidomide (5/9). The first hematological response, and the best hematological response were observed after 26 days (range 11–125), and after 157 days (range 35–659), respectively. The hematological overall response was 100% (7/9 CR, 2/9 VGPR). After 3 years 8/9 patients are alive. Median therapy duration was 753 days, treatment is ongoing in 3/9 patients. Cardiac response is present in 5/9 patient; renal response is present in 3/9 patients, respectively.
Venetoclax is an effective treatment option for patients with relapsed/refractory AL amyloidosis with t(11;14) and BCL2 expression. Venetoclax leads to a deep hematologic response and to improvement of organ function. Overall survival at 3 years was exceptionally high at 88.9% in this intermediate- to high-risk cohort.
Abstract
Topic: Prognosis AL
Background: A difference between involved and non-involved free light chain (dFLC) exceeding 180 mg/L is part of the 2012 Mayo staging system. We hypothesized that depth of response in AL amyloidosis patients treated with bortezomib-containing regimens are independent of free light chain burden.
Methods: This is a retrospective, multicentre study including 223 newly diagnosed AL amyloidosis patients seen at our institutions between 2012 to 2024. We investigated the relationship between baseline iFLC and dFLC at day 28 and 3, 6, 9 and 12 months from commencement of CyBorD or DaraCyBorD therapy. The study was IRB approved.
Results: We identified 132 patients treated with CyBorD and 91 treated with DaraCyBorD. Forty patients in the CyBorD cohort and 3 in the DaraCyBorD cohort did not respond to therapy. Lack of response was independent of baseline iFLC. At day 28, we identified no correlation (r2 = 0.02) between baseline iFLC and dFLC response in patients receiving DaraCyBorD (Fig 1A), while patients receiving CyBorD had lower cytoreduction (r2 = 0.53), particularly when iFLC measured >1000 mg/L (Fig 1B). Similar trends were noted at 3, 6, 9 and 12 months from therapy start.
Conclusion: Depth and rapidity of response is independent of iFLC at diagnosis in patients treated with DaraCyBorD. Response in CyBorD treated patients is weakly dependent on baseline iFLC at exceedingly high values. Data from our cohort are not mature to assess overall survival, but it questions the importance of free light chain burden measured by conventional methods (sFLC) in the era of DaraCyBorD.
Copyright for this individual abstract is: © 2024 Brigham and Women’s Hospital. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
Compositional changes in the gut microbiome, frequently observed in amyloid diseases, can induce chronic inflammation and increased gut barrier permeability. This altered composition is known to modulate communication between the gut and the brain. Within the gut microbiome, both as common inhabitants and pathogens, are species that produce functional amyloids. Rather than arising as a misfolding, functional amyloids have evolved to produce amyloid structures. Bacterial functional amyloids exploit the structural properties of amyloid to aid in biofilm formation. A proposed mechanism behind this process is cross-seeding, where preformed fibrils from one amyloid protein template the misfolding of another monomeric amyloid protein.
Here we investigate the ability of both FapC and CsgA, the major components of Fap and curli fibres respectively, to cross-seed amyloid-β, α-synuclein and Medin. We assess alterations in aggregation kinetics by ThT assay, fibril morphology in both seeded and non-seeded conditions by transmission electron microscopy (TEM) and assess secondary structure changes by fourier transform infrared spectroscopy (FT-IR). Additionally, we assess their associated cell toxicity across neuronal and epithelial cells.
We show that FapC and CsgA can alter the aggregation kinetics and fibril morphology of amyloid-β and medin in vitro. We report that cross-seeded fibrils show distinct secondary structure by FT-IR. Additionally, we observe altered cell toxicity for cross-seeded amyloids along with cell-type dependent toxicity of functional amyloid proteins. This data contributes to understanding how functional amyloids could influence amyloid disease and also provides insights into cross-seeding as a mechanism for disease initiation and progression.
Abstract
Topic: Prognosis ATTR
Recent studies have reported atrial involvement and coexistence of aortic stenosis in transthyretin (ATTR) cardiac amyloidosis (CA). However, pathological reports of extraventricular ATTR amyloid deposits in atrial structures or heart valves are limited, and the clinical implications of ATTR amyloid deposits outside the ventricles are not fully elucidated.
We report 3 cases of extraventricular ATTR amyloid deposits confirmed in surgically resected aortic valves and left atrial structures, all of which were unlikely to have significant ATTR amyloidosis infiltrating the ventricles as determined by multimodality evaluation including 99mtechnetium-pyrophosphate scintigraphy, cardiac magnetic resonance, endomyocardial biopsy and their mid-term clinical course up to 5 years (Table). These findings suggested that these were extraventricular ATTR amyloid deposits localized in the aortic valve and the left atrium.
While long-term observation is required to fully clarify whether these extraventricular ATTR amyloid deposits are truly localized outside the ventricles or are early stages of ATTR-CA infiltrating the ventricles, our 3 cases with multimodality evaluations and mid-term follow up suggest the existence of extraventricular ATTR amyloid deposits localized in the aortic valve and left atrial structures.
Abstract
Topic: Prognosis ATTR
Background: Delays in diagnosis in ATTR-CM may be region-specific and different outcomes have been reported.
Aim: To provide data about patients with ATTR-CM in Greece, evolving patterns, and secular trends in their clinical and demographic characteristics.
Methods: This is a single-center observational study including all patients with ATTR-CM presenting in the Department of Clinical Therapeutics, from 01/2014 to 12/2023. Genetic testing was performed in all cases.
Results: One-hundred and forty-two ATTR-CM patients were included (85% males, median age 82, 15% females, median age 85); 16 (11%) carried TTR mutations (25% had Val30Met). Numbers of diagnoses increased significantly after 2017. The majority (84%) presented with heart failure and 55% with atrial fibrillation, 9% had aortic stenosis, 87% had extracardiac manifestations (48% musculoskeletal disorders, 36% symptoms suggestive of peripheral neuropathy and 31% gastrointestinal symptoms). Those diagnosed after 2018 had lower NTproBNP, lower National amyloidosis Center (NAC) stage, and a higher male:female ratio. Eighty (56%) patients started tafamidis treatment, 12 (8.5%) with other stabilizers and 6 (4%) inotersen. Median follow-up is 31 months; 3-year survival is 58%. Advanced NYHA class and NAC stage-3 were associated with poorer survival (log-rank p < .05) – there was no difference between NAC stage-1 and stage-2. Age, eGFR <45 mL/kg/m2, NTproBNP >5000 pg/mL (in all log-rank p < .02) were associated with worse survival, in both whole cohort and tafamidis-treated subgroup.
Discussion: Our analysis shows a shift to diagnosis at a less advanced stage; however, more efforts are needed to facilitate early diagnosis. National registries are important to understand diagnostic and treatment gaps.
Abstract
Topic: Prognosis AL
The treatment of patients with AL amyloidosis is now based on evidence derived from clinical trials. However, in this heterogeneous disease inclusion criteria can select subgroups that differ from the real-world population affecting the generalizability of results.
We evaluated the proportion of newly diagnosed patients ineligible for phase III trials and the impact of common exclusion criteria on overall survival (OS).
The analysis was performed on the prospectively maintained ReAL registry (NCT04839003) including all patients treated from 2004 to 2021. Exclusion criteria derived from phase III trials were considered (table 1).
A total of 1726 consecutive patients were included (table 1). Of them, 846 (49%) met at least one exclusion criterion. Median follow-up of the entire cohort was 34 months (95% CI: 29–41 months). Median OS was significantly longer in eligible patients (79 vs 10 months, p < .001), even excluding IIIb cardiac stage patients (78 vs 21 months, p < .001). The survival advantage remained significant across all cardiac stages, both in the overall population, stage I (175 vs 62 months, p < .001), II (69 vs 35 months, p = .002) and IIIa (38 vs 7 months, p < .001), and in subjects enrolled after 2009, stage I (not reached vs 60 months, p < .001), II (73 vs 34 months, p = .001) and IIIa (38 vs 6 months, p < .001).
Almost 50% (36% of stage I-IIIa) of real-world patients with AL amyloidosis are excluded from upfront phase III trials. Excluded patients have a worse outcome across cardiac stages. Trials should endeavor to broaden inclusiveness to improve the generalizability of results.
Abstract
Topic: Prognosis AL
Background: In 2018 we have started a national registry on amyloidosis.
Objectives: Our aim for this analysis was to analyse outcome of newly diagnosed patients with AL and ATTRwt amyloidosis in Germany and validate prognostic factors in a real-world setting.
Methods: The registry population consist of all reported cases of newly diagnosed amyloidosis patients between 04.01.2018 until 31.03.2020. Inclusion criteria were either a Congo Red positive tissue sample or unequivocal findings in bone scintigraphy for ATTR.
Results: Of 1200 registered patients 1158 patients fulfilled inclusion criteria. Of those, 527 patients had systemic AL and 459 patients ATTRwt amyloidosis. Median OS was 64 and 59 months for AL and ATTRwt, respectively, after a median follow-up of 55 months. Multivariate analyses (including age, cardiac stage and paraprotein parameters for AL patients) revealed the following significant parameters: higher age for AL and ATTR (HR 1.04; and HR 1.08; p < .001), higher cardiac stage (I versus III) for AL and ATTR (HR 3.1; HR 6.99; p < .001), IgM type (versus no heavy chain) for AL (HR 2.9; p = .01), while there was no diffence between kappa and lambda AL.
Conclusion: The National registry is the first prospective evaluation of newly diagnosed patients in Germany. We could confirm that advanced cardiac involvement has a negative influence on OS in AL and ATTRwt reflecting the diagnosis at a late stage. We have started an extended registry in 2020 including biopsy reports of reference pathologists to estimate the incidence of AL and ATTR amyloidoses in Germany.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: The true prevalence of obstructive coronary artery disease (CAD) in cardiac amyloidosis (CA) is still underestimated. This study aimed to assess the prevalence, clinical relevance, and outcome of CAD in CA-patients.
Methods: We retrospectively analyzed the CAD prevalence in CA-patients in six Austrian amyloidosis centers. We also investigated differences in cardiac biomarkers, ECG, and clinical characteristics in patients with and without CAD. Survival was further investigated in a single center.
Results: 337 patients with CA (ATTR 72%, AL 28%) were included, with coronary angiography available in 204 (61%) patients. 96 of them (47%) were diagnosed with severe CAD. There was a stark difference in CAD prevalence between the ATTR and AL cohort (ATTR 51% vs. AL 35%, p = .041). There were no significant differences in clinical symptoms (p = .545), functional capacity (6-min-walk-test, p = .196), and ECG (pseudoinfarction pattern, p = .404) between patients with and without CAD. In the ATTR-cohort, the presence of CAD was associated with higher NT-proBNP levels (p = .019). In a single-center outcome analysis including 132 patients, no significant difference was observed in the mortality rate between patients with CAD (18% deaths) and those without CAD (25% deaths) (p = .939).
Conclusion: CAD is highly prevalent in CA-patients with a significant difference between ATTR and AL. The higher prevalence in ATTR is possibly due to the older age in this group. The presence of a pseudoinfarction pattern (ECG) did not serve as a reliable indicator of CAD. The presence of CAD must be considered in CA-patients.
Abstract
Topic: Diagnosis ATTRwt
Introduction: Transthyretin amyloidosis (ATTR) is a progressive, multisystem disease caused by gene variants (ATTRv) or age-related wild-type transthyretin (ATTRwt) amyloidosis. Patients are benefitting from recent advances in treatment and increased disease awareness; however, their diagnostic journey is often lengthy and challenging. This analysis examined the diagnostic journey of patients recently diagnosed with ATTR amyloidosis in a cross-sectional study.
Methods: In 2022 and 2023, the Amyloidosis Research Consortium conducted online surveys of amyloidosis patients. Data collected included demographic, clinical characteristics, symptoms, and diagnostic journey. Recently diagnosed included patients diagnosed January 2021–May 2022 in the 2022 survey and patients diagnosed June 2022–November 2023 in the 2023 survey.
Results: Of the 2093 total respondents, 228 (11%) were recently diagnosed with ATTR amyloidosis (115 and 113 patients in the 2022 and 2023 surveys, respectively). Of those, 176 (77%) were diagnosed with ATTRwt amyloidosis and 52 (23%) with ATTRv amyloidosis. (). Mean (Standard Deviation [SD]) time from symptom onset to ATTRv amyloidosis diagnosis was 3.3 (3.2) and 2.2 (3.2) years in the 2022 cohort and 2023 cohort, respectively. Similarly, the mean (SD) time from symptom onset to ATTRwt amyloidosis diagnosis was 3.3 (6.6) and 2.4 (3.4) years in the 2022 cohort and 2023 cohort, respectively.
Table 1. Patient demographic and clinical characteristics of patient with AL amyloidosis recently diagnosed by survey year.
Conclusion: These findings suggest that while the time to diagnosis from symptom onset is still lengthy, it may be improving for ATTR amyloidosis patients. Further studies are needed to evaluate the impact of increased disease awareness on earlier diagnosis and treatment interventions on patient outcomes.
Abstract
Topic: Diagnosis ATTRwt
Background: Male hypogonadism (HG), characterized by low testosterone levels, increases in prevalence with age. The prevalence is high among patients with unspecified heart failure, with an estimate of 20–50%. The prevalence is unknown in ATTR-CM. We therefore sought to determine the prevalence of HG in men with ATTR-CM.
Methods: Serum total testosterone (TT) and free testosterone (FT) were measured in consecutive patients evaluated in a single amyloidosis program. TT was measured by liquid chromatography-tandem mass spectrometry, and FT by equilibrium dialysis. HG was defined as TT <8 nmol/L, or an equivocal TT, 8–12 nmol/L, with FT <220 pmol/L. FT >12 nmol/L was considered normal. Subjects were divided into tertiles by age: <70 (youngest age 56), 70–80 and >80 years.
Results: Among 135 patients, mean age 75 ± 7, the prevalence of HG was 51/135 (37%). The majority of those with HG (42/51) had equivocal TT levels with low FT. HG was present in 7/34 (21%) in those age 56–70, 30/77 (39%) age 71–80 and 14/31 (47%) over age 80.
Conclusions: 1. Hypogonadism is common in ATTR-CM patients, increasing with age. 2. Most HG patients have equivocal TT levels in the range often considered ‘low normal’, but had abnormally low FT. Thus, measurement of FT as well as TT is mandatory. 3. The high prevalence of HG probably represents the known association of HG with heart failure, but other factors cannot be excluded. Further investigation into the clinical correlates and prognostic significance of hypogonadism in ATTR-CM, and the effect of correction, is warranted.
Abstract
Topic: Treatments of AL
Introduction: Daratumumab, an anti-CD38 monoclonal antibody, has recently been approved by FDA and EMA for first-line treatment of systemic light chain (AL) amyloidosis in combination with cyclophosphamide, bortezomib and dexamethasone (Dara-CyBorD). In this case series we share our experience in treatment of AL amyloidosis with Dara-CyBorD.
Case series: From August 2022 to January 2024 overall 10 patients (6 female) with newly diagnosed AL amyloidosis received treatment with the Dara-CyBorD regimen. Age ranged from 44 to 74 years at the beginning of treatment (median 57 [IQR 53–62]). One patient was diagnosed in Mayo2004/European stage I, three patients in stages II, IIIA, IIIB each. Two patients (both stage IIIB) died due to complications associated with amyloid-related organ damage; 8 patients continue treatment. All patients achieved at least a very good partial hematologic response after the first cycle of Dara-CyBorD, 7 patients achieved complete response. In 5 cases, sustained organ response was achieved (cardiac in patients #1, #2, #5, #7; renal – #7, #9). Tolerability was acceptable, no serious adverse events were registered.
Conclusion: Daratumumab in combination with CyBorD has been demonstrated as a well-tolerated and effective therapy regimen for newly diagnosed AL amyloidosis. Rapid satisfactory hematologic responses were seen in all cases; sustained cardiac response was seen in select individuals regardless of initial disease stage.
Abstract
Topic: Prognosis AL
Introduction: Halting amyloid production, measured by hematological response (HR), and the degree of pre-existing renal damage, assessed by renal stage, are crucial to renal responses (RenRs) in AL amyloidosis. However, substantial variability in RenRs is unexplained by HR or renal stage. We investigated factors associated with deep and timely RenRs.
Method: Retrospective study of newly diagnosed AL amyloidosis patients eligible for RenR between 2010 and 2022. RenRs were recorded at 6, 12, 24-months and the best RenR achieved. Multivariable logistic regression models for any RenR (≥RenPR) at 6-months and deep RenR (≥RenVGPR) at 12, 24-months and best response were created using best subset selection.
Results: 356 patients were included with a median age of 63-years (IQR:57–68) and median follow-up of 5.4-years. On univariate analysis, high dFLCs, kappa isotype, deep HR within 6-months and frontline stem-cell transplantation (ASCT) were significantly associated with an increased likelihood of any RenR at 6-months. High dFLCs, kappa isotype, ASCT, deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at 12 or 24-months. ASCT, a deep HR within 6-months and low renal stage were significantly associated with an increased likelihood of a deep RenR at best response. The multivariable model is shown, Table 1.
Discussion: HR and less advanced organ involvement are reliable indicators of timely and deep RenRs. In addition, transplantation, kappa isotype and high dFLCs predict RenR. The association between dFLCs and light-chain isotype with RenR implicates light-chain toxicity in organ damage and repair in AL amyloidosis.
Abstract
Topic: Imaging
Subtopic: MRI
Introduction and purpose: The prevalence and significance of right heart dysfunction in patients with cardiac amyloidosis (CA) remains uncertain. The current study sought to establish the extent of right heart involvement using echocardiography and cardiac magnetic resonance imaging (CMR).
Methods: Patients with confirmed CA by biopsy or cardiac imaging, who had concurrent echocardiography and CMR at Mayo Clinic from 2020 to 2021 were included. Clinical echocardiographic and CMR parameters were collected. Additional CMR parameters analyzed using CVI42 software package.
Results: A total of 30 patients were included: 22 males (73%), median age was 76 years. 13 (43%) AL and 17 (57%) (16 wild-type and one hereditary ATTR). Five patients have died. By echocardiography, mild or greater RV enlargement was present in 23%, RA enlargement in 54%, moderate or greater TR in 13% and pulmonary hypertension in 23%. By CMR, the median indexed RVEDV was 72 mL/m2, RVEF 49% and RV wall strain -19%. Myocardial delayed enhancement (MDE) was common in LV (77%), RV (48%) and RA (44%).
RVEF at CMR was lower in ATTR than AL (46% v. 54%, p = .06), as well as RA-EF (34% v. 46%, p = .017). RVSP was significantly higher among those patients who died (mean 50 mmHg v. 32 mmHg, p = .005).
Conclusion: Right heart dysfunction is prevalent in CA. More studies are needed to determine the independent prognostic significance of right heart imaging parameters.
Copyright for this individual abstract is: © 2024 Mayo Clinic. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Diagnosis AL
Introduction: Latvia is a Northern European country with a 1.9 million population. An observational cohort study was started in January 2020 with long-term follow-up of patients referred to Pauls Stradiņš Clinical University Hospital, the main referral center for amyloidosis in Latvia.
Methods: Inclusion criteria were any systemic or localized amyloidosis confirmed by tissue biopsy with Congo red stain or a positive 99mTc-PYP scan for transthyretin (ATTR) amyloidosis.
Results: 54 patients were included, 26 (46%) females. 20 patients (37%) died during follow-up. The most prevalent type was light chain (AL) amyloidosis (n = 33 [61%]) with 26 cases of systemic disease and 7 localized. The greatest proportion (n = 9 [38%]) of AL cases were diagnosed at stage IIIb (Mayo2004/European). AA was diagnosed in 9 patients, ATTR in 7, two of them with TTR mutations (Arg54Thr, Val30Met). One case of lysozyme amyloidosis was registered.
Kidney involvement was present in 37 (69%) cases, cardiac in 27 (50%), polyneuropathy in 21 (39%), orthostatic hypotension in 12 (22%). Mortality was not associated with type but was associated with mean age: 60 ± 14 years in survivors versus 68 ± 8 in non-survivors.
We observed an increase in AL and ATTR cases and a decrease in AA with AL dominating as the leading type in 2022–2023. Our data demonstrates a relatively small proportion of ATTR.
Conclusions: Since the initiation of the national registry, amyloidosis has become more widely recognized as a clinical condition in Latvia with increasing incidence of AL type. ATTR remains underdiagnosed.
Abstract
Topic: Diagnosis ATTRwt
Background: Recent advances in imaging and increased disease awareness have led to a significant rise in newly diagnosed cases of cardiac amyloidosis (CA). However, comprehensive epidemiological data on the disease's true incidence are lacking.
Methods: Suspected CA cases underwent diagnostic work-up in 20 Centers in Tuscany and Umbria within the CARRY registry, from January 1st to December 31st, 2022.
Results: Out of 551 subjects enrolled, 448 had complete diagnostic data, revealing CA in 179 (40%) patients: 28 (16%) light chain CA, 114 (64%) wild-type transthyretin CA, 12 (7%) variant transthyretin CA, and 25 (13%) undetermined CA. The estimated cumulative incidence was 39.6 cases per million inhabitants per year (2022 population in Tuscany and Umbria =4,518,388, according to the Italian National Institute of Statistics). Alternative diagnoses included hypertensive heart disease (n = 157, 58%), hypertrophic cardiomyopathy (n = 25, 9%), moderate-to-severe valvular heart disease (n = 11, 4%), or a mixed phenotype (n = 72, 27%). Primary referral pathways for CA suspicion were cardiological (n = 345, 77%), incidental finding (n = 58, 13%), and hematology referral (n = 33, 7%). Patients with confirmed CA were older and more frequently reported musculoskeletal red flags, such as carpal tunnel syndrome and spontaneous tendon rupture. Median time to diagnosis from suspicion was similar for CA and alternative diagnoses (73 [37–140] vs. 84 [36–156] days).
Conclusions: CA diagnoses are increasing globally, with an estimated cumulative incidence of 39.6 new cases per million inhabitants per year in two large Italian regions. These findings should inform policymakers in redefining CA as a rare disease, potentially influencing patient care and treatment costs.
Abstract
Topic: Prognosis AL
Introduction: Hematological response (HR) is an imperfect predictor of cardiac response (CaR) in AL amyloidosis, as anti-plasma cell therapies halt amyloid production without removing existing deposits. CaR is strongly associated with survival, but substantial variation exists in response kinetics. We investigated variables associated with timely and deep CaRs.
Method: Retrospective study of newly diagnosed AL amyloidosis patients eligible for CaR between 2010 and 2022. CaRs were recorded at 6, 12, 24-months and the best CaR at any timepoint. Multivariable logistic regression models for any CaR (≥CarPR) at 6 months and deep CaR (≥CarVGPR) at 12, 24-months or best response were created using best subset selection.
Results: 403 patients were included with a median age of 64-years (IQR:58–70), male preponderance (64%) and median follow-up of 5.3-years. On univariate analysis, bone-marrow plasma-cells (BMPCs ≥20%), dFLC ≥60 mg/dL, <6-months from first medical encounter to diagnosis, obtaining ≥ hemVGPR within 6-months, autologous stem-cell transplant, and high-risk cytogenetic abnormalities (HRCAs) were significantly associated with an increased likelihood of any CaR at 6-months. These variables as well as kappa isotype and low cardiac stage were significantly associated with an increased likelihood of obtaining a deep CaR at best response on univariate analysis. The multivariable model is shown, Table 1.
Discussion: Our results indicate that high plasma cell burden, HRCAs, deep HR and early diagnosis leads to more timely CaRs. The association between a ‘myeloma phenotype’ and CaR kinetics, endorses the role of direct light chain toxicity as one mechanism of cardiac damage.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Social determinants of health contribute to outcome disparities, yet their impact on time to diagnosis in transthyretin cardiac amyloidosis (ATTR-CA) remains unexplored. Using a cohort of Medicare fee-for service patients, we assessed the time from first heart failure (HF) diagnosis to ATTR-CA diagnosis, stratified by social vulnerability index (SVI), race, geographic location, and household income.
Methods: This retrospective study uses de-identified patient claims data from 1 January 2015–31 December 2022, from patients, aged ≥65 years, with ≥1 claims for HF or cardiomyopathy, ≥2 claims on distinct service dates for wtATTR-CM, hATTR-CM, or organ-limited amyloidosis and ≥1 year of continuous Medicare enrollment. Patient claims for any other form of amyloidosis, multiple myeloma, or plasma cell dyscrasias were excluded.
Results: 6732 met the inclusion criteria. Patients were organ-limited (70.5%), wild-type (22.9%), and hereditary (6.7%). The mean (SD) time from HF to ATTR-CA diagnosis was consistent across races ranging from 18.4 (21.8) to 20.8 (21.6) months. Socioeconomic status by the SVI showed mean diagnosis times of 20.3 (21.4) (lowest SVI; least vulnerable), 20.4 (21.2) (low SVI), 19.0 (20.7) (high SVI), and 21.4 (21.8) months (highest SVI; most vulnerable). Rural settings had a mean time to diagnosis of 20.8 (21.6) months compared to 20.1 (21.2) months in urban areas. Income disparities revealed diagnosis times of 21.7 (22.1) months ($0–$49,999), 19.9 (20.9) months ($50,000–$99,999), and 19.6 (21.1) months ($100,000+).
Discussion: These findings underscore the need to address social determinants of health via multivariable analyses to evaluate potential differences that may impact patient care.
Abstract
Topic: Treatments of Other More Rare Amyloidoses
In order to characterize the spectrum of amyloidosis types, clinical presentations and treatments in genitourinary (GU) tract amyloidosis, we reviewed our center’s experience spanning 30 years and 101 biopsy-proven cases. Amyloid typing was performed on available tissue samples. Localized light chain (ALoc) amyloidosis was defined as amyloid deposition limited to one site without signs of amyloid-related systemic disease or markers of plasma cell dyscrasia. Cases of amyloid derived from hepatic proteins – e.g. transthyretin (TTR), serum amyloid A (SAA), apolipoprotein A1 (AApoA1) – were designated as systemic disease, as were cases fulfilling the diagnostic criteria for systemic light chain (AL) amyloidosis.
Of 101 patients with GU amyloidosis, 53% (n = 54) had ALoc amyloidosis; 19% (n = 19) had systemic AL amyloidosis; 25% (n = 25) had transthyretin amyloidosis; 4% (n = 2) had serum AA amyloidosis; and 1 had AApoA1 amyloidosis. Hematuria was the presenting feature in 99% of lower GU tract (bladder) cases, whereas flank pain was most common (55%) in cases of upper GU tract amyloidosis.
Seven patients with ALoc amyloidosis underwent low-dose (20 Gy) external beam radiotherapy (EBRT). Of the three bladder patients who underwent EBRT none required surgical intervention after EBRT. In the four patients with ureter involvement there was one intervention after EBRT, palliative nephrectomy for ongoing pain due to chronic hydronephrosis. Compared to ALoc amyloidosis, patients with systemic disease (ATTR, AL or AA amyloidosis) underwent surgical resections less frequently (6% versus 56%) as management efforts were focused on decreasing the production of and/or stabilizing the amyloidogenic precursor proteins.
Abstract
Topic: Prognosis ATTR
Background: The clinical landscape of transthyretin (ATTR) amyloidosis has changed considerably since the FDA approval of various transthyretin stabilizers and silencers from 2018 onwards. This study describes trends in overall survival (OS) among patients with wild-type (ATTRwt) and variant (ATTRV122I and non-V122I-ATTRv) ATTR amyloidosis.
Methods: We identified patients diagnosed with ATTR amyloidosis between 1960–2022 from a prospectively maintained database at the Boston University Amyloidosis Center. Patients were grouped according to time period of diagnosis (pre-2000, 2000–2010, 2011–2017, and 2018–2022). Trends in OS were described across ATTR subtypes using Kaplan-Meier analyses and compared using log-rank tests (reference group: 2018–2022).
Results: Among a total of 1034 patients with ATTR amyloidosis, 486 (46.7%) had ATTRwt amyloidosis, 137 (13.2%) had ATTRV122I amyloidosis, and 413 (39.8%) had non-V122I-ATTRv amyloidosis. The mean (SD) age in years at diagnosis was 75.6 (7.0), 71.4 (9.0), and 55.5 (12.9) among patients with ATTRwt, ATTRV122I, and non-V122I-ATTRv amyloidosis, respectively. Median OS was shortest (3.3 years) for patients with ATTRV122I amyloidosis and longest (7.7 years) for patients with non-V122I-ATTRv amyloidosis (Figure 1A). Across ATTR subtypes (Figure 1B–D), no diagnosis time period group had a significant difference in OS versus the 2018–2022 group; however, median OS was not reached by the 2018–2022 group in ATTRwt and non-V122I-ATTRv amyloidosis subtypes.
Figure 1. Kaplan–Meier estimates of overall survival (OS) stratified by ATTR amyloidosis subtype (panel A) and time period of diagnosis for each ATTR amyloidosis subtype (panels B–D).
Notes: Follow-up began at the date of ATTR amyloidosis diagnosis. Patients were censored at end of follow-up (assessed 11/2022) or last known clinical visit or contact date. Comparisons to reference groups (ref.) were computed by log-rank tests.
Abbreviations: OS, overall survival; CI, confidence interval; NR, not reached.
Conclusions: Longer prospective follow-up is needed to establish the OS impact of changing care standards and emerging treatments for ATTR amyloidosis under real-world conditions. This study is limited by single-referral center bias and potential changing referral patterns over time.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Introduction: Early Phase Clinical Trial units classically engage healthy volunteers to undertake First in Human clinical trials. With the advent of direct acting therapies such as gene editing drugs there has been a shift to first in patient trials, often with significantly longer follow up visits. Having has started undertaking gene editing trials in Amyloidosis patients, necessitating a change in practices to provide an equitable experience.
Methods: From September 2023 a patient panel was formed to gather feedback, this consisted of a quarterly meeting to answer structured questions and monthly meeting collecting unstructured feedback. Feedback from these sessions was shared across the unit to allow teams to create solutions to improve areas patient could be improved. This resulted in feedback questionnaire being redesigned to be more user friendly while retaining the same questions, adding a new question to gain feedback on whether patients felt they were fully informed of the procedures, study drug and safe requirements.
Results: Data was compared to identify changes to feedback from implementing patient panel suggestions for research volunteer questionnaires (0–5 scoring system) between 2021 and September 2023 (1048 responses) and September 2023–January 2024. (151 responses). There was 9% improvement overall, 17% increase in patient understanding their visit and 13% increase in likely to recommend taking part in research.
Conclusion: Engaging patients to have a voice in their needs as research participants is an important tool in ensuring a good experience to retain patients in studies and motivate them to participate in future trials.
Abstract
Topic: Basic Science ATTR
The study of the circulating transcriptome provides a snapshot of the molecular processes occurring in an individual at a given time using minimally invasive approaches. Consequently, the analysis of gene expression profiles in patients with ATTR amyloidosis potentially allows us, not only to investigate the molecular mechanisms underlying the etiopathogenesis of the disease, but also to identify potential diagnostic biomarkers. To date, the number of studies investigating gene expression profiling in cardiac TTR amyloidosis is limited. This is particularly notable in the study of small RNAs expression profiles, where only targeted approaches have been applied. Here, by using high throughput RNA sequencing methods, we have generated the transcriptional profile of both cell-free RNA in plasma and circulating RNAs carried into extracellular vesicles (EV) from patients with cardiac ATTR-wt (n = 20), and ATTR-v (n = 20) amyloidosis. Differential miRNA and gene expression analyses were performed comparing the ATTR amyloidosis groups with patients with cardiac involvement other than amyloidosis (n = 20) and healthy volunteers (n = 20). Additional functional enrichment analyses of both RNA species were carried out using Gene Ontology. While differential gene expression of protein coding genes was limited to EV-carried RNAs, changes in miRNAs expression were found in both cell-free and EV-carried RNAs. Moreover, 88 miRNAs were found differentially expressed in ATTR by both approaches. Importantly, some miRNAs were differentially expressed in both ATTR-wt and ATTR-v amyloidosis, being potential biomarkers currently under study. Interestingly, the pathways related to histone modifications and those associated to protein catabolism by the proteasome were enriched in all the comparisons.
Abstract
Topic: Pathology
Background: Salivary gland amyloidosis is uncommon, usually representing involvement by systemic amyloidosis.
Design: We retrospectively identified 57 salivary gland amyloidosis cases, including major and minor salivary glands, typed using proteomics-based method between 2010 and 2022. Frequency of amyloid types, clinicopathologic features, and distribution pattern of amyloid deposits were assessed.
Results: Of the 57 cases (20 male/35 female/2 unknown; mean age 64.9 ± 11.7 years), indication for biopsy/resection was known in N = 34, including suspected amyloidosis (N = 14), lesion/mass (N = 12), swelling/enlargement (N = 5), and rule out Sjögren syndrome (N = 3). Concurrent pathology was present in 16/34 cases with available data: chronic sialadenitis (N = 11), extranodal marginal zone lymphoma (N = 3), plasma cell neoplasm (N = 1), and pleomorphic adenoma (N = 1). We identified 3 types of amyloidosis: immunoglobulin light chain/AL (N = 47; 82.5%); immunoglobulin heavy and light chain/ALH (N = 1; 1.8%), and transthyretin/ATTR (N = 9; 15.8%). Patterns of salivary gland amyloid deposits were assessed in 35 cases with available slides, which included: 1) Interstitial, perivascular, and/or periductal (N = 18; 51.4%); 2) Macronodular or mass formation (N = 9; 25.7%); 3) Stromal small nodule formation (N = 7; 20.0%); and 4) Extensive diffuse interstitial involvement (N = 1; 2.9%). We also identified one case of primary amyloidosis localized to bilateral submandibular salivary glands.
Conclusion: Although salivary gland amyloidosis is uncommon, it may be underrecognized due to low index of suspicion. Although as expected a large proportion of the salivary gland amyloidosis were AL, we also identified a subset of ATTR cases. Therefore, proteomics-based typing remains essential as morphologic overlap exists among the amyloid types encountered in salivary gland amyloidosis.
Table 1. Indication for Salivary Gland Biopsy/Resection by Amyloid Type (N = 34).
Abstract
Topic: Diagnosis AL
Background: Typing of amyloid proteins by mass spectrometry represents the first clinical application of proteomics in diagnostics. Since the initial method was published ∼15 years ago, numerous centers worldwide have adopted similar techniques.
Purpose: At the Referral Center of Amyloidosis in Greece, our objectives were to 1) establish proteomic typing of amyloid proteins for diagnostic purposes and 2) explore the benefits of employing library-free Data-Independent Acquisition (DIA) to simultaneously address research questions.
Methods: We recently implemented a proteomic analysis (Canetti et al., 2020) of laser-microdissected amyloid depots using nano LC coupled with a timsTOF fleX mass spectrometer. Over one hundred paraffin-embedded biopsies from various tissues, including subcutaneous fat, kidney, salivary gland, lung, and heart, were analyzed. Leveraging the capabilities of Parallel Accumulation–Serial Fragmentation (PASEF) technology, we routinely utilize library-free DIA, expanding protein detection from the typical ∼100 protein groups in Data-Dependent Acquisition (DDA) to 800+.
Results: This presentation outlines the challenges associated with establishing such an assay for newcomers and our validation approach in a clinical setting. Following successful replication of diagnostic results from 14 fat tissue biopsies of patients with various AL, as analyzed by the UK National Amyloidosis Centre in London, we are continually expanding our internal validation cohort. The increased sensitivity that has been achieved aids diagnostics in cases of scarce deposition and allows for better characterization of tissue substructures’ proteomes for research purposes. Capitalizing on the data, we are exploring the spatial distribution of proteins, as well as new patterns of potential diagnostic and/or prognostic value.
Abstract
Topic: Diagnosis AL
Introduction: Subcutaneous fat aspiration is a minimally invasive screening tool utilized by amyloidosis centers to screen for systemic amyloidosis (SA). Aspirates are typically performed at only at centers.
Methods: Sensitivity and specificity for consecutive fat aspirates performed between November 2020 and January 2024 at the amyloidosis clinic in Oldenburg (OL) were evaluated at the amyloidosis center Heidelberg (HD). Samples were sent within a sealed syringe via courier from OL to HD accompanied by an informed consent form. For sensitivity analysis patients with SA proven by either histopathology or scintigraphy and for specificity analysis patients with clinically certain exclusion of SA were chosen. Aspiration and analysis were performed according to (1).
Results: A total of 16/25 probes from patients with proven SA and 14/82 probes from patients with suspected SA (see Table) were classified as positive. All positive screening probes originated from patients with an underlying monoclonal gammopathy (MG) and in eleven of the cases could be confirmed as systemic light-chain (AL) amyloidosis. In four patients with negative screening probes amyloid was detected in another biopsy.
An overall sensitivity of 68% (25/40) and a specificity of 100% (11/11) were achieved. Additionally, 3/56 probes from patients with MG and clinically possible SA showed amyloid deposits.
For subtypes, sensitivities were: systemic AL 78% (25/32), systemic wild-type transthyretin 0% (0/4) and systemic SAA 50% (2/4). Sensitivity was 90% (9/10) in females (only AL) and 60% (18/30) in males.
Conclusion: Externally performed fat aspirates analyzed at an experienced center yield a good sensitivity for systemic AL.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: Cardiac involvement is common in systemic AL and the most critical prognostic factor predicting poor survival. Standard non-invasive imaging of the myocardium includes echocardiogram and cardiac MRI, however case reports describe cardiac inflammation demonstrated with 18F-FDG PET/CT. We investigated the utility of inflammatory protocoled 18F-FDG PET/CT (undertaken after 18 h of low carbohydrate diet) to detect myocardial inflammatory light chain proteotoxicity in AL amyloidosis.
Methods: Patients undergoing 18F-FDG PET/CT with the ‘inflammatory’ protocol at diagnosis and at 6-month follow up with a diagnosis of systemic AL amyloidosis at University College London Hospitals were reviewed.
Results: Fifteen patients (10 male, 5 female) underwent 18F-FDG PET/CT between 2021 and 2023. Age at diagnosis was 68 years (range 53–78), Mayo stages were stage II, IIIA, IIIB in 1, 9 and 5, respectively. At a median follow up 20 months (range 1–24), 5 patients died (4 stage IIIB; 1 stage IIIA) during follow-up at a median of 8 months (range 1–18) from diagnosis.
Baseline scan at diagnosis demonstrated myocardial uptake that was homogenous (n = 5), heterogenous (n = 9) patchy or no uptake (n = 1). Six-month follow-up scans were performed in 11 patients: 5 improved, 4 worsening, 2 stable uptakes. 2/4 with worsening uptake died after 6-month scanning. 3 patients died prior to this time point and one patient is awaiting a scan.
Conclusion: Patients with systemic AL amyloidosis with cardiac involvement demonstrate features of inflammation by 18F-FDG PET/CT. Worsening uptake and new, patchy increased metabolic activity particularly within the left ventricle may suggest worsening cardiac inflammation and outcome.
Abstract
Topic: Prognosis AL
Introduction: Traditional staging in systemic AL amyloidosis have focussed on cardiac biomarkers (troponin T, NT-proBNP) and light chain burden (difference in involved and uninvolved free-light chain, dFLC) as the major determinants of patient survival. Recently the functional assessments, global longitudinal strain (GLS%) and 6-min walk distance (6MWD) have also been shown to be prognostic. We assessed the prognostic value of these biomarkers in a uniformly bortezomib-treated patient population.
Methods: Patients enrolled in a prospective observational study at the United Kingdom National Amyloidosis Centre treated with bortezomib-based regimens from 2010–2019 were analysed. Overall survival (OS) was defined as time from diagnosis to death/last follow-up.
Results: 1298 patients were treated between 2010 and 2019 with a median age of 67 years (29–89), 2 (1–5) organs involved: 834 (64%) cardiac, 907 (70%) renal involvement. Median dFLC was 189 mg/L (0–15,989), NTproBNP 1520 ng/L (12–93,602), troponin 54 ng/L (0–742), 6MWD 393 m (19–700). 219, 447, 433 and 198 were Mayo stage I, II, IIIA, IIIB, respectively. Median OS was 82 months (95% CI 65–110). On univariable analysis the following variables were strongly predictive of survival (p < .001): dFLC >180 mg/L, modified Mayo staging, GLS%, 6MWD >350 m. However, on multivariable analysis, 6MWD >350 m (p = .001), GLS% (p < .001) and modified Mayo (p < .001) remained independently predictive and dFLC >180 mg/L (p = .90) was no longer predictive of overall survival ().
Table 1. Multivariable model predicting overall survival.
Conclusion: In the bortezomib-treatment era, GLS%, 6MWD >350 m and modified Mayo staging (troponin, NTproBNP) appear independently predictive and dFLC >180 mg/L does not appear to be independently predictive of overall survival. Further analysis in the daratumumab era is warranted.
Abstract
Topic: Basic Science AL
Aggregation of antibody light chain proteins is the hallmark of amyloid light chain (AL) amyloidosis. Patient-derived amyloid fibrils are formed from light chain variable domain residues in non-native conformations. Therefore, light chains must first unfold from their native structures in order to aggregate. We investigated how the processes of unfolding and self-assembly are linked using a well-studied light chain variable domain protein known as WIL, derived from a patient with AL amyloidosis. WIL readily aggregates in vitro under conditions where the native state predominates. Aggregation kinetics, measured using thioflavin T fluorescence, exhibited a lag phase followed by a rapid increase in fluorescence. We measured the effects on aggregation rate from altering protein concentration and adding pre-formed WIL fibril ‘seeds’. WIL aggregation had a distinctly non-linear dependence on concentration, with a maximum aggregation rate (i.e. a minimum lag phase duration) observed at 8 µM protein concentration. This behavior is consistent with formation of alternate aggregate structures in the early phases of amyloid formation. Addition of N- or C-terminal peptide tags did not greatly affect the folding or stability of the protein, but these tags altered the concentration dependence of aggregation. Aggregation rates increased in the presence of pre-formed seeds, but adding seeds did not eliminate the lag phase even when the proportion of seeds to soluble protein was greater than 1 in 1600. The complexity of aggregation observed in vitro highlights how multiple species may contribute to amyloid pathology in patients.
Copyright for this individual abstract is: © 2024 Boston University Amyloidosis Center. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Prognosis AL
Background: In AL amyloidosis, sustained long-term hematologic remission can be achieved even with conventional therapies.
Aim: To identify clinical characteristics that are associated with long-term hematologic remission ≥5 years, without the use of ASCT.
Methods: We analyzed 210 consecutive patients with AL, treated without ASCT, with ≥5 years of follow-up, excluding patients who survived <6 months and focusing on patients who: had not had hematologic PD, not received salvage therapy, were still alive or had died from causes unrelated to AL.
Results: Long-term hematologic remission rate was 17%(n = 35); clinical characteristics are shown in the Table. Median duration of primary therapy was 7.5 (4–21) months vs 5.6 (0.5–21) for patients without long-term remission (p < .001); for patients that received lenalidomide was 9.7 (5–12) vs 7.1 (0.5–17) months (p = .023). Hematologic response to 1st line therapy was ≥ VGPR in 33 (94%) patients (CR:22, VGPR:11) vs 46%(p < .001), was ≥ VGPR with dFLC <10 mg/L in 18 (51%) vs 20%(p < .001) while 6 (17%) had only low dFLC VGPR. At 1- and 3-month landmarks, 24 (68%) and 27 (77%) of those in long-term remissions had achieved ≥ VGPR (vs 43 (33%) and 62 (46%), p < .001). MRD (available in 19 patients) was undetectable in 11 (31%) [vs 3 (2%) of the non-sustained remission group, p < .001]. Cardiac response was observed in 9/19 (47%) patients and renal response in 18/30 (60%); however, 7 (20%) initiated dialysis despite deep hematologic responses.
Conclusion: Early, profoundly deep hematologic responses and prolonged therapy seem to be associated with long-term remissions using conventional therapies only. These data also underscore the role of prolonged therapies in which lenalidomide may be important as part of a maintenance strategy.
Table 1. Baseline clinical characteristics.
Abstract
Topic: Prognosis ATTR
Background: Natriuretic peptides (NPs) are prognostic biomarkers in ATTR-CM. Patients in atrial fibrillation (AF) have higher levels on NPs compared to patients in sinus rhythm (SR), but AF is not independently associated with survival in ATTR-CM. Currently there is limited data about the interaction between NPs, AF, and survival in patients receiving tafamidis.
Methods: This is a retrospective study, including 193 patients (85% males) with ATTR-CM receiving tafamidis from 2016 to 2023. N-terminal pro-B natriuretic peptide (Nt-proBNP) was measured at time of diagnosis. We assessed the impact of AF on survival by Kaplan Meier curves and log-rank test, uni- and multivariable Cox regression. ROC curves were constructed to determine the optimal Nt-proBNP cut off for death prediction.
Results: Median age was 77.00 (73.25–83.00) years with 76 patients being in SR and 118 in AF. Patients in AF presented significantly higher median levels of Nt-proBNP (2484 vs 1515 pg/mL, p < .001). In the total cohort, AF was not associated with worse survival (Figure A). After ROC curve analysis, Nt-proBNP >2500 pg/mL was predictive of death. Following subgroup analysis, in patients with Nt-proBNP >2500 pg/mL, those in AF presented worse survival (Figure B), but lost significance after Cox regression adjusted for age, genotype, glomerular filtration rate and Nt-proBNP levels. The presence of AF was not associated with worse survival in patients with Nt-proBNP <2500 pg/mL (Figure C).
Conclusion: Even though atrial fibrillation is associated with higher levels of NPs; its presence does not modify their prognostic significance in patients with ATTR-CM receiving tafamidis.
Abstract
Topic: Treatments of ATTR
Introduction: Therapy for hereditary transthyretin (ATTRv) amyloidosis changed the history of neuropathy. Concerning ATTRV30M patients with nephropathy, albuminuria is a key feature for outcome. The anti-albuminuric effect of tafamidis was established, but its sustainability after switching therapy was not regarded. Our aim was to review the recurrence of albuminuria after converting tafamidis to other therapies.
Methods: Retrospective cohort study of ATTRV30M patients that started tafamidis from July-2012 to March-2019 and had urinary albumin/creatinine ratio (ACR) ≥ 30 mg/g at baseline. End of follow-up: June-2023, liver transplantation, end-stage kidney disease (ESKD) or death; criteria to switch therapy was the progression of neuropathy. Patients participating in clinical trials were not considered.
Results: Six male and 32 female, aged 47 (40.5–58.9) years-old, treated with tafamidis had ACR ≥30 mg/g at baseline; the median eGFR CKD-EPI creatinine and cystatin C was 91.5 (71.2–115) mL/min/1.73 m2; At the end of follow-up 40% remained on tafamidis, four patients died, two underwent liver transplantation, two evolved to ESKD. 15 switched therapies. Twelve patients started patisiran and three underwent a clinical trial. After the switch to patisiran, albuminuria didn't recur, except in one patient, whose kidney biopsy excluded disease besides amyloidosis; the median eGFR at the time of switch and at end of follow-up was, respectively, 82 (68.5–94.3) mL/min/1.73 m2 and 80 (70.8–93) mL/min/1.73 m2; no patient needed renal replacement therapy, neither death was registered.
Conclusions: In this cohort, the tafamidis switch to siRNA therapy showed maintenance of the albuminuria remission and stabilization of eGFR. The findings suggest that the pathogenic derangement caused by glomerular and vascular ATTR-amyloidosis is dynamic and not limited to the deposits.
Abstract
Topic: Prognosis ATTR
Background: Arrhythmias is a significant disease component of wild-type transthyretin amyloidosis (ATTRwt). However, there is limited contemporary ATTRwt specific data on the incidence of pacemaker implantations (PMI) after diagnosis and the prognostic value of pacemakers at the time of diagnosis. We investigated the risk of PMI after ATTRwt diagnosis and the prognostic value of having a pacemaker at the time of diagnosis.
Methods: All patients with ATTRwt who was treated at Aarhus University hospital in the period from 2017 to 2022 were enrolled (N = 203). Relevant clinical data was prospectively registered in an ATTRwt database. Pacemaker data and mortality data were retrospectively collected. All-cause mortality was based on Kaplan-Meier estimates. Cumulative incidence of PMI was estimated with death as a competing risk. PMI within 35 days after diagnosis was defined as prevalent PM at diagnosis.
Results: Patients with or without pacemaker at the time of diagnosis were not significantly different in terms of age, sex, or major comorbidity. Patients with pacemakers at diagnosis had slightly more advanced ATTRwt disease with respect to clinical stage and echocardiographic parameters. Having a pacemaker at time of diagnosis was associated to an adverse prognosis for patients with ATTRwt (Figure 1A – age-and sex adjusted HR 2.24). We found a high incidence of pacemaker implantations with 12% receiving a PMI within the first 2 years after diagnosis (Figure 1B).
Conclusion: We conclude that patients with ATTRwt have a high incidence of pacemaker implantations after diagnosis and that having a pacemaker at time of diagnosis is a marker of adverse prognosis.
Abstract
Topic: Treatments of ATTR
Introduction: Studies of sodium-glucose co-transporter 2 inhibitors (SGLT2i) therapy on ATTR kidney and heart disease are scarce and focus wild-type and V122I. In ATTRv, namely V30M, SGLT2i introduction to preserve kidney function or improve cardiorenal syndrome is not an outlined practice. We assessed the safety and clinical evolution, based on a staging score system, of SGLT2i therapy in ATTR V30M amyloidosis
Methods: Patients with biopsy proven ATTR V30M amyloidosis and criteria for SGLT2i started standard dosages. Gillmore score (GS) for ATTR cardiomyopathy, kidney failure risk equation (KFRE) and the renal system score (RSS) of the FASTEX model (Fabry disease) were calculated. We recalculated GS using CKD-EPI creatinine and CKD- EPI cystatin C. Tc-99-DPD scintigraphy was used to estimate heart amyloid load.
Results: Eight patients (4 males) were following on median of 11,9 months; 3 had positive DPD scintigraphy, all males, who presented with a late-onset of symptoms, echocardiographic features of cardiac amyloidosis, and increased NT-proBNP. Cardiovascular and renal adverse events were absent. Neurogenic bladder was present in 3 patients, 2 had uncomplicated urinary tract infections; 1 had symptomatic hypotension, leading to discontinuation of therapy. Baseline line characteristics and clinical evolution are summarized in table1.
Conclusions: In this pilot study, we evidenced that ATTR V30M patients meet the criteria for SGLT2i therapy. Dysautonomia and neurogenic bladder were not an impediment for therapy. In addition to disease modifying drugs, SGLT2i may improve kidney and cardiovascular outcomes in ATTR V30M amyloidosis, across distinct clinical phenotypes.
Abstract
Topic: Prognosis ATTR
Background: Atrial fibrillation (AF) is a significant disease component of wild-type transthyretin amyloidosis (ATTRwt). Nonetheless, only few studies have investigated the incidence of AF after the time of diagnosis and the prognostic value of AF at time of diagnosis. Therefore, we investigated the cumulative risk of AF at 1–3 years after diagnosis and the prognostic value of AF at the time of diagnosis.
Methods: All patients with ATTRwt who was treated at Aarhus University Hospital in the period from 2017 to 2022 were enrolled (N = 203) and most relevant clinical data was prospectively registered in an ATTRwt database. AF data and mortality data were retrospectively collected. All-cause mortality was based on Kaplan-Meier estimates. Cumulative incidence of AF was estimated with death as a competing risk. AF within 35 days after diagnosis were defined as prevalent AF at time of diagnosis.
Results: At diagnosis patients with or without AF were similar regarding age and sex, but prevalent AF was associated to more progressed ATTRwt disease with respect to symptoms (NYHA), clinical stage (NAC) and echocardiographic parameters at diagnosis. We found AF at diagnosis to be a significant marker of poor prognosis for patients with ATTRwt (Figure 1A, age and sex adjusted HR of 1.89). We also found a high 3-year-cumulative incidence of AF (44%) after diagnosis (Figure 1B).
Conclusion: We conclude that patients with ATTRwt have a high incidence of AF after diagnosis and that having AF at time of diagnosis is a significant marker of worse prognosis.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognised cause of heart failure. 99mTc-DPD scintigraphy, due to its exquisite sensitivity for ATTR-CM forms a critical part of the accepted diagnostic algorithm. Therefore, there is substantial interest in utilising Tc-DPD scintigraphy to track treatment response. We conducted a multimodality study assessing utility of 99mTc-DPD in tracking treatment response in ATTR-CM.
Methods: We identified ATTR-CM patients at the UK National Amyloidosis Centre retrospectively who were receiving disease modifying therapy and had pre- and post-treatment 99mTc-DPD/SPECT-CT. Myocardial percentage injected dose (PID), a proposed marker of amyloid burden, was measured as previously described. Patients were split into three tertiles according to absolute change in PID at follow-up relative to baseline. At time of Tc-DPD scintigraphy, patients underwent assessment with echocardiography and blood biomarkers. A subset of patients had cardiac magnetic resonance (CMR) imaging available.
Results: Sixty-six patients (median age 66 years) ATTR-CM patients receiving treatment (43 patisiran, 14 inotersen, 10 tafamidis) with serial 99mTc-DPD scans were identified. No statistically significant correlation between the change in PID at follow up and a wide range of echocardiographic, biochemical and CMR parameters was identified. Discordance between a reduction in PID and clinical, imaging, and biochemical parameters was common. (Figure 1). Furthermore, no statistically significant correlation (assessed with Spearman's and Pearson's correlation coefficients) was detected PID change and other parameters.
Conclusion: Our study suggests that a reduction in 99mTc-DPD uptake at follow up is not correlated with a wide range of established biomarkers of treatment response in ATTR-CM.
Abstract
Topic: Diagnosis ATTRv
Cardiomyopathy and peripheral neuropathy with dysautonomia are major clinical manifestations of transthyretin amyloidosis (ATTR). ATTR may be caused by mutations in transthyretin gene (variant ATTR, ATTRv) or may occur with normal transthyretin genotype (wild-type ATTR, ATTRwt). Clinical manifestations of ATTRv are influenced by genotype, but there is a variation in phenotype and penetrance, and ATTRwt presents mainly with amyloid cardiomyopathy. Additionally, clinical symptoms of ATTR patients may be caused by other disorders, including other types of amyloidosis. We present 3 patients with ATTRwt and ATTRv carrier status and major clinical manifestations caused by non-ATTR diseases. Patient 1 was a 71-year-old man with wtATTR cardiomyopathy and severe dysautonomia with pure autonomic failure caused by alpha-synuclein deposition. Patient 2 was a 59-year-old man with chronic diarrhea, sensorimotor polyneuropathy and amyloid cardiomyopathy caused by IgA lambda multiple myeloma. Genetic testing also showed that he is a heterozygous carrier of p.V142I transthyretin mutation, but biopsies of the gastrointestinal tract, endomyocardium and salivary gland showed only IgA lambda amyloid deposition. Patient 3 was an 18-year-old woman with paresthesias, and numbness associated with entrapment neuropathies. Electrodiagnostic testing showed bilateral carpal tunnel syndrome and bilateral ulnar nerve entrapment at the elbow. Genetic testing showed heterozygous deletion of PMP22 gene associated with hereditary neuropathy with liability to pressure palsies (HNPP), and heterozygous p.V142I transthyretin mutation. Neurologic examination showed mild distal sensory polyneuropathy attributable to HNPP. Our case series demonstrates a broad spectrum of non-ATTR conditions that can manifest with clinical manifestations similar to ATTR complications.
Abstract
Topic: Diagnosis AL
Background: Light chain amyloidosis can manifest as localized (Loc-AL) or systemic (Sys-AL) disease. Loc-AL is typically indolent, affecting non-vital organs, while Sys-AL is life-threatening, involving organs like heart and kidneys. Although locoregional recurrences of Loc-AL or progression to Sys-AL are described, the reverse is less common. We report a case of Sys-AL relapsing as Loc-AL.
Case: In June 2020, a 63-year-old man presented with dyspnea, fatigue, weight loss, anasarca, and macroglossia starting 6 months earlier. Cardiac imaging revealed a ventricular septum of 14 mm, left ventricular hypertrophy, apical sparing, and late gadolinium enhancement. Stage IIIb/IV Sys-AL was confirmed by the detection of amyloid deposit in the bone marrow (BM), subtyped as lambda by mass spectrometry. Free light chains lambda and kappa measured 807.3 and 13.2 mg/L, BM clonal plasma cells 15%, normal FISH, NTproBNP 9349 ng/L, Troponin-hs 238 ng/L. Daratumumab-VCD therapy was started, with hematologic CR after 3 cycles. Daratumumab was administered up to 24 cycles as in Andromeda, with sustained CR and best cardiac response observed after 2.5 years (NTproBNP 166 ng/L). One year after Daratumumab discontinuation, a CT scan to evaluate pneumonia detected an axillary mass, confirmed by chest MRI as a 15 × 8.5 × 7.5 cm thoracic mass. Biopsy revealed amyloid deposit (ongoing mass spectrometry). No clonal plasma cells were observed in BM, Kappa/lambda ratio and cardiac biomarkers were normal, and Immunofixation showed IgG kappa.
Conclusion: This case represents an unusual presentation of AL amyloidosis, initially manifested as systemic, later relapsing as localized following Daratumumab-VCD therapy.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: AApoAIV amyloidosis is rare and can be difficult to diagnose as ApoAIV is both an amyloidogenic protein and an amyloid signature protein. Recently, a fibrillogenic ApoAIV signal sequence identified by proteomic analysis was proposed as an AApoAIV amyloidosis marker.
Aim: To characterize the demographics, organ distribution, and proteomic features of AApoAIV amyloidosis, including sensitivity and specificity of the ApoAIV signal sequence.
Materials and Methods: The proteomic features of all Congo red-positive tissue specimens typed by LC-MS/MS in the Mayo Clinic reference laboratory between January 2016 and December 2020 (n = 21,854) were reviewed.
Results: There were 73 (0.33%) heart, kidney, or duodenum specimens with a bona fide pathologic and proteomic diagnosis of AApoAIV amyloidosis. Median age at diagnosis was 71 years (range 54–93); with 55 males and 18 females (M:F = 3:1). The ApoAIV signal sequence was identified in 68/73 cases (93%), including all 30 kidney cases (100%), 17/21 heart cases (81%), and 16/17 duodenal cases (94%). The ApoAIV signal sequence was identified in 10/21,854 specimens (0.05%) diagnosed with another amyloid type. Anatomic sites were diverse. One heart biopsy proved to have two amyloid types (ATTRwt and AApoAIV); the others were suspected to have a component of AApoAIV in addition to the known amyloid type (AL (N = 8) and AB2M (N = 1)).
Conclusions: AApoAIV amyloidosis is rare and primarily involves kidney, heart, and duodenum. The fibrillogenic ApoAIV signal sequence has high sensitivity (93%) and specificity (>99%) for AApoAIV amyloidosis, thus serving as an excellent proteomic marker of this disease.
Abstract
Topic: Diagnosis AL
Background: Systemic amyloidosis (SA) is often underdiagnosed and recognized late in middle-income countries. Limited access to specific tests makes the diagnostic journey a challenge. Precisely identifying the precursor protein is even more difficult, as mass spectrometry (MS) is not widely available. We aimed to retrospectively subtype amyloid by MS and evaluate the performance of a clinical-laboratory model (CLM) in amyloid typing.
Methods: Biopsies were randomly selected from a cohort of 143 patients diagnosed with SA from 2009 to 2020 at Hospital das Clínicas da Universidade de Sao Paulo, a Brazilian university hospital. Previous diagnoses and medical records were reviewed. CLM defined amyloid subtype by immunohistochemistry, indirect immunofluorescence, or genetic mutation. When diagnostic criteria couldńt be met, typing relied on available data and clinical judgment.
Results: Forty-nine biopsies were included from different organs (kidney 31%, heart 20%, subcutaneous fat 12%, gastrointestinal tract 10%, nerve 8%, lung 8%, lymph node, bone marrow, liver, salivary gland and tongue 2% each). MS identified the following subtypes: AL (57%, n = 28), ATTR (25%, n = 12), AA (6%, n = 3) and AFib (2%, n = 1). Five cases were inconclusive due to poor quality of samples. The CLM correctly subtyped amyloid in 100% of AL, AA and AFib, and 75% of ATTR cases. Three patients with ATTR were misdiagnosed as AL, and one received anti-plasma cell agents.
Conclusion: Despite the good performance of CLM observed in our study, we emphasize the role of MS as the gold standard method to accurately subtype amyloid, avoiding potential harm from misdiagnosis and incorrect treatment.
Abstract
Topic: Imaging
Subtopic: Cardiac
Introduction: Cardiac amyloidosis (CA) results of amyloid fibrils deposition in the myocardium. The main subtypes are light chain (AL-CA) and transthyretin (ATTR-CA). This study aimed to assess clinical, laboratory, imaging parameters and outcomes of CA in a middle-income country.
Methods: We retrospectively reviewed medical records of consecutive patients diagnosed with systemic amyloidosis (SA) between 2010 and 2020 at a private hospital in Sao Paulo, Brazil. Patients were included when criteria for AC were met (positive cardiac biopsy or presence of amyloidosis multimodality imaging red flags). Characteristics were described for patients with AL-CA and ATTR-CA. All patients consent to publication after ethical approval CAAE 58091122.4.0000.5455.
Results: Among 48 patients with SA, 16 were included (8 ATTR-CA, 8 AL-CA). Average age was 74.6 (± 11.5) years, ATTR-CA patients were older and 82% were male. Besides CA, most common clinical manifestations were neurologic (50%) and renal (44%) disorders and more common with AL-CA. Previous heart failure was more common with ATTR-CA and CKD with AL-CA. Cardiac biomarkers troponin and natriuretic peptides were altered in 54% and 100% respectively. Multimodality imaging red flags were present in 69% of ECG (11/16), 81% of ECHO (13/16), 100% of Cardiac MRI (8/8) and 89% of PYP bone scintigraphy (8/9) and were more common with ATTR-CA. After mean follow up of 4 years (1–12 years) 5 patients died (31%).
Conclusions: This study highlights the role of multimodality imaging of CA. AL-CA and ATTR-CA, despite progress in the diagnosis and treatment, remain associated with poor prognosis.
Abstract
Topic: Pathology
Background: Monoclonal antibodies, which are primarily IgG kappa, cause confusion upon testing blood and urine by immunofixation. A gel shift assay exists for daratumumab, but such methodology is not practical in the face of >6 therapeutic monoclonal antibodies (t-mAb) in the plasma cell disorder space. Our group and others have shown that blood mass spectrometry is helpful to distinguish t-mAb from intrinsic M-proteins. Fortunately, this is less of an issue in AL amyloidosis, a condition in which the majority of patients have lambda restricted clones.
Goal: To describe the behavior of daratumumab by M-quant among patients with AL amyloidosis.
Methods: We interrogated our Mass-Fix and amyloidosis databases to find patients who satisfied the following criteria: (1) Previously untreated AL Amyloidosis; (2) Daratumumab use; (3) Mass-Fix testing along with quantitative IgG immunoglobulin; (4) At least 3 measurements satisfying above criteria; (5) Patients’ agreement to have their records reviewed.
Results: The study set included 36 patients with 346 measurements (figure, upper panel dara M-quant; lower, iFLC by FLC assay). Of those measurements, 13 were done after daratumumab had been discontinued (median 3.2 months (range of 1 to 7.8 months)). Median M-quant of daratumumab among patients with ongoing therapy was 13.4 mg/dL (IQR 6.2, 48) mg/dL. There appeared to be a difference in daratumumab M-quant among nephrotic and non-nephrotic patients.
Conclusions: Daratumumab is not only detectable, but it is also measurable by blood mass spectrometry. Levels appeared to be lower among nephrotic and non-nephrotic patients.
Abstract
Topic: Treatments of ATTR
Introduction: Formed in 2019, the Amyloidosis Forum is a public-private partnership between the Amyloidosis Research Consortium (ARC) and the US Food and Drug Administration (FDA) with a shared goal of accelerating development of new treatments and diagnostics for light chain (AL) and transthyretin (ATTR) amyloidosis.
Objective: The Forum fosters collaboration between academia, industry, patients, and health agencies to address scientific gaps and unmet research needs for amyloidosis.
Methods: The Forum, chaired by ARC and led by a multidisciplinary Steering Committee, convenes cross-stakeholder working groups to advance key topics and disseminate findings through public meetings and peer-reviewed publications.
Results: To date, the Forum has conducted an overview of the approaches to advance drug development in AL and ATTR amyloidosis in an evolving treatment landscape. Working groups have identified novel endpoints and analysis methodology in AL amyloidosis, developed a federated analytics platform to evaluate potential biomarkers as clinical endpoints, and explored standardization of imaging techniques for clinical trials. Proceedings from public meetings (available at www.amyloidosisforum.org) and working group activities have resulted in numerous peer-reviewed publications and conference presentations.
Conclusions: The Forum provides a unique opportunity for mutually beneficial collaboration across a diverse group of stakeholders by facilitating innovation through exchange of scientific knowledge in amyloidosis. The Forum seeks to expand participation and identify future priorities based on community input.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Characterization of light-chain (AL) and transthyretin (ATTR) amyloid deposits in the heart and systemic organs is currently challenging. This study evaluates the novel PET radiotracer 124I-evuzamitide for quantifying AL and ATTR amyloid burden in the heart and systemic organs.
Methods: The study included 24 patients (12 AL, 12 ATTR) and 16 healthy controls who underwent 124I-evuzamitide PET/CT at 5 h post-injection (median 0.98 mCi). The liver, spleen, kidneys, heart, pancreas, and adrenal glands were automatically segmented using a trained deep learning algorithm (AIQ Solutions). Mean standardized uptake value (SUV) in each organ was normalized by the average aortic arch uptake to obtain ratio SUVR measurements. Abnormal uptake was defined as mean +1.96SD in the controls.
Results: 124I-evuzamitide demonstrated excellent sensitivity in detecting cardiac amyloidosis, identifying 24/24 patients. It also identified abnormal uptake in the liver (3/12 AL and 1/12 ATTR), spleen (5/12 AL), kidneys (4/12 AL), pancreas (7/12 AL), and adrenal glands (6/12 AL and 1/12 ATTR) (Table 1). Compared to the International Society of Amyloidosis criteria for organ involvement in AL, 124I-evuzamitide identified more patients with hepatic involvement and fewer patients with renal involvement (2/5, 40%). Notably, it detected abnormal renal uptake in two patients without biochemical signs of renal involvement. The novel findings of abnormal pancreatic and adrenal uptake indicate 124I-evuzamitide's potential for early amyloidosis detection in these organs.
Conclusions: 124I-evuzamitide PET/CT is highly sensitive for detecting amyloid deposits in the heart and systemic organs, providing a novel noninvasive approach for characterizing cardiac and systemic organ amyloid burden.
Abstract
Topic: Diagnosis AL
Background: Blood mass spectrometry is a major advance in the field of plasma cell disorders, including AL amyloidosis. We and others have published on the sensitivity of Mass-Fix and QIP-MS in this space, but we now describe in AL the value of M-quant, a means by which mass spectrometry can provide a quantitative measure of immunoglobulins at low levels.
Methods: We evaluated patients who had a diagnosis of untreated amyloidosis, MASS-FIX run in our lab, and consent to review their medical records. To calculate the M-quant, a simultaneous nephelometric quantitative immunoglobulin measurement was required. Figure 1a shows patient selection.
Results: Of the 105 AL patients, 70 had an M-spike on SPEP, and 95 had an M-quant calculated. Respective median (IQR) were 0.7 (0–1.7) g/dL and 641 (121–1533) mg/dL for SPEP M-spike and M-quant. Spearman’s rho of M-quant versus SPEP M-spike is 0.9479 (figure 1B). Of the 35 patients with an unmeasurable SPEP M-spike, 25 had a reportable M-quant (median 99 (IQR 36–295) mg/dL). For these 25 patients, distributions of immunoglobulins were: IgG/IgA/IgM, 60%/36%/4%; and lambda/kappa 80%/20%. For the same 25 patients, the median ratio of involved/uninvolved-FLC using the Binding Site FLC assay was 9.1 (IQR 2.3–33.4) mg/dL.
Conclusions: Understanding M-quant utility in AL is in its earliest stages. At present, the assay does not incorporate a free light chain measure, but it can provide information on the size of M-proteins only relegated to ‘positive’ or ‘negative’ by either immunofixation or by blood mass spectrometry.
Abstract
Topic: Imaging
Subtopic: Cardiac
Introduction: 18F-fluorodeoxyglycose (FDG)/13N-ammonia cardiac positron emission tomography/computed tomography (PET/CT) scan is routinely used for diagnostic evaluation and surveillance of inflammatory cardiomyopathies such as cardiac sarcoidosis. We report a case of wild-type transthyretin (TTR) cardiac amyloidosis (CA) with positive 18F-FDG/13N-ammonia cardiac PET/CT.
Case: 85-year-old male with supraventricular tachycardia ablation, non-sustained ventricular tachycardia, non-obstructive coronary artery disease and presumed isolated cardiac sarcoidosis diagnosed 3 years ago (based on delayed gadolinium enhancement on cardiac magnetic resonance imaging and myocardial inflammation with perfusion abnormalities on 18F-FDG/13N-ammonia cardiac PET/CT (Figure A)) on methotrexate presented for evaluation of fatigue and dyspnea. Physical examination was unremarkable. High sensitivity troponin-T was 39 ng/L (25 ng/L 3 years ago) and NT-proBNP was 1279 pg/mL (268 pg/mL 3 years ago). Electrocardiogram (ECG) showed sinus rhythm with elevated artificial intelligence-enhanced ECG probability for amyloid (0.98 versus 0.34 3 years ago; detection threshold >0.48). Repeat 18F-FDG/13N-ammonia cardiac PET/CT demonstrated resolution of myocardial inflammation (Figure B). Echocardiogram showed normal biventricular chamber size/function but increased concentric left ventricular (LV) wall thickness (18 mm)/mass and decreased LV global longitudinal strain of −16% compared to prior study. These findings raised suspicion for CA leading to a 99mTechnetium Pyrophosphate scan which was strongly suggestive of CA (Figure C–E). Screening for light chain CA and testing for TTR gene were negative. Methotrexate was discontinued and Tafamidis was started.
Discussion: Reasons for a positive 18F-FDG/13N-ammonia cardiac PET/CT scan may include underlying inflammation related to pathophysiology of cardiac amyloidosis, difficulty suppressing physiological myocardial 18F-FDG uptake due to amyloid infiltration and/or co-existent inflammatory cardiomyopathy.
Abstract
Topic: Diagnosis AL
Background: Amyloidosis can present in a myriad of ways initially with non-specific symptoms, sometimes leading to delayed or initially incorrect diagnosis. Neurologically, subacute presentations can potentially be confused with other conditions including AIDP or CIDP. We present two such cases (AL and TTRv).
Methods: Two patients with subacute onset of sensory and motor deficits were evaluated. Both had prior history of chronic stable distal lower limb sensory symptoms for 2 or more years attributed to other conditions.
Results: Both patients were admitted to the hospital for concern of either AIDP or CIDP. Electrophysiological studies suggested a severe subacute on chronic axon loss polyradiculoneuropathy pattern in both patients. No demyelinating features were noted. Both had CSF protein elevation. The subacute decline and clinical findings lead to consideration of immune therapy use for both. One previously healthy patient had fatigue and weight loss and mild lambda light chain elevation. Nerve biopsy was obtained. Immune therapy tried empirically without benefit. Biopsy subsequently positive for amyloid deposition.
The other patient had a history of atrial fibrillation, CHF, spinal surgery, and bilateral carpal tunnel syndrome, leading to cardiac PYP scan consistent with TTR amyloid. Immune treatment deferred. TTR gene testing subsequently positive.
Conclusion: These cases illustrate the potential for a subacute neurological presentation of both AL and TTRv amyloidosis. Increasing clinical awareness of this type of presentation may expedite correct diagnosis, treatment initiation and avoidance of therapies ineffective for amyloidosis.
Abstract
Topic: Pathology
Introduction: Diagnostic delays are common in amyloidosis, however recognition of ‘red flag’ symptoms can offer opportunities for earlier diagnosis. In systemic amyloidosis, gastrointestinal (GI) involvement may occur and can herald an underlying unrecognized amyloidogenic disease process. We hypothesized that prospective Congo red staining of GI tissue samples may serve as an effective means of opportunistic screening for amyloidosis and may improve the detection rate of early disease.
Methods: This was a prospective cross-sectional study that enrolled consecutive patients over the age of 35 undergoing clinically indicated endoscopy for characteristic GI symptoms seen in amyloidosis including unexplained weight loss, unexplained diarrhea, alternating constipation/diarrhea, early satiety, gastroparesis, and new-onset irritable bowel syndrome within the last year in patients over age 50. Patients were consented for Congo red staining of clinically indicated tissue samples.
Results: A total of 100 patients underwent clinically indicated GI mucosal biopsies, of which 97 were stained with Congo red. Enrolled patients had a mean age of 49.5 years with 64% female and 11% black. A total of 181 GI biopsies were collected with the most common locations being the colon (73%), stomach (44%), duodenum (33%) and jejunum (14%). After Congo red staining, no biopsies stained positive.
Conclusion: This study represents our single center experience of an active ascertainment strategy to detect amyloid deposits in patients presenting with ‘red flag’ GI symptoms. We demonstrated that utilizing GI biopsy as an initial diagnostic tool is not a useful screening strategy.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Given amyloidosis can be a multi-system disease, the workup brings challenges especially for patients with multiple co-morbidities. We present a case of localized iatrogenic amyloidosis in a patient with features commonly associated with systemic amyloidosis.
Case Report: A 70-year-old male with progressive dyspnea, cardiomyopathy, and monoclonal gammopathy presented to clinic for workup. Past medical history included carpel tunnel syndrome, coronary artery disease, chronic kidney disease, and obesity (previously on liraglutide). Workup showed IgA kappa monoclonal protein, elevated kappa light-chains (108.8 g/L), and an NTProBNP 843 ug/mL. Cardiac MRI showed LVEF 27%, multiple sessile thrombi, with normal T1/T2 mapping. BMA showed 5–10% kappa-restricted plasmacytosis suggestive of smoldering myeloma, congo-red negative. Fat pad biopsy detected amyloid deposition however, mass spectrometry could not determine a sub-type. Immunohistochemistry was performed showing negative to insulin and positive to glucagon. Given the homology between liraglutide and glucagon, inability to detect additional amyloid sub-type, and patient's history, a diagnosis of GLP-1 amyloidosis was made. PYP scan done 3- months post-diagnosis was not suggestive of ATTR amyloidosis. The patient was optimized by cardiology for the thrombi discovered on MRI. He remains off liraglutide indefinity.
Conclusion: The was the first case of GLP-1 amyloidosis described in Canada. Given his history and comorbidities it would be easy to assume the underlying pathology was systemic amyloidosis (1), highlighting the importance of sub-typing. This case raises caution as the use of GLP-1 agonists for weight loss has risen steadily in the developing world. (2)
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: AIns is a rare iatrogenic amyloidosis. Compared to more common types of amyloidosis it is unknown if AIns is associated with cancer development. We present a case of concomitant AIns and lymphoma.
Case Report: 70-year-old female with a 20-year history of DMII presented with abdominal pain, increasing insulin requirements, and an A1c of 10.2%. CT showed small-bowel mesenteric mass, subcutaneous fat density, and multiple mediastinal nodes. Core biopsy of the fat mass showed amyloid (Figure 1) and mass spectrometry showed AIns. PET/CT showed multiple FDG-avid nodes in the chest and inguinal fossa. Later biopsy of an inguinal node showed grade 1–2/3 follicular lymphoma. A watch-and-wait approach was adopted, and insulin was rotated to thigh injection. Three-months post diagnosis, her A1c had improved, and insulin requirements decreased by 50%.
Figure 1. (A) Hematoxylin and eosin stain of core needle biopsy of subcutaneous soft tissue mass (4×). (B) Polarized Congo red stain of tissue from core needle biopsy of subcutaneous soft tissue mass (10×).
One-year post she reported acute-onset back pain with CT scan showing a paravertebral mass. Core biopsy demonstrated DLBCL. She underwent standard R-CHOP chemotherapy, with final restaging PET scan showing CMR.
Discussion and Summary: To our knowledge, this is the first case describing AIns and concurrent widespread nodal lymphoma. Certain types of amyloidosis, particularly AL, are associated with other cancers. The frequency of co-occurring AIns and malignancy is unknown. A case series of iatrogenic amyloid noted serum amyloid P-component (SAP) in most patients studied. SAP is associated with underlying autoimmune and inflammatory conditions and possible predisposition to cancer formation. SAP activation within AIns tissue may contribute to cancer pathogenesis and malignancy formation. Further research is needed to understand this possible association.
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Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Background: Treatment of amyloidosis is dependent on isolating the sub-type. Often, targeted biopsies are needed for sub-type confirmation, but the sensitivity of the chosen tissue biopsy site can vary. Transverse carpel ligament and tenosynovial biopsies from the wrist have recently become a high-yield site for obtaining an ATTR diagnosis; however, less is known for AL amyloidosis. We present a case of dual amyloidosis diagnosed via wrist biopsies.
Case Report: An 88-year-old male presented in 2023 with heart failure (NYHA class III; ECOG 3), NTProBNP 30,000 ng/mL, and PYP scan suggestive of ATTR amyloidosis (HCC ratio of 1.98; Grade 2). Fat pad biopsy negative. Too unwell for cardiac biopsy, wrist biopsies were obtained showing both ATTR and AL amyloidosis. Tafamidis was chosen to treat his ATTR amyloid and treatment for his AL amyloid included weekly Rituximab x4 weeks targeting B-cell clone followed by CyBorD-Daratumumab for light-chain reduction. After 1-month of Tafamidis and 1 dose of Rituximab, he as hospitalized for deconditioning and Tafamidis was discontinued per his request. He tolerated the final doses of Rituximab and 1 cycle of CyBorD-Daratumumab. He attained a PR after the first cycle and, given his age, CyBorD was discontinued in favor of Daratumumab monotherapy. To date, he has attained a VGPR. He has improved functionally by walking 1–2 km per day.
Conclusion: This is the first case of dual amyloidosis diagnosed in Canada and the first case of AL amyloidosis diagnosed via wrist biopsies at our Centre. Future research is needed on the approach to dual amyloid treatment.
Abstract
Topic: Imaging
Subtopic: Echo
Background: The left ventricle (LV) shortens longitudinally throughout systole, then lengthens almost immediately after aortic valve closure (AVC) (Figure 1A). Longitudinal strain (LS) is routinely measured in cardiac amyloidosis (CA) and often shows ‘apical sparing’. We noted a novel pattern of longitudinal contractile diastasis (LCD) in which systolic LS stops early, and relaxation onset is delayed (Fig 1B). The significance of this pattern is unclear.
Aim: To characterize LCD in patients with CA.
Methods: Strain imaging (EchoPac) was performed in 35 CA patients. Time from systolic nadir of LS to AVC was defined as systolic diastasis, and from AVC to onset of myocardial relaxation as diastolic diastasis, and total as LCD.
Results: 35 randomly chosen patients were studied (AL =21, ATTR =14), median age 72, 65% male. Median NT-proBNP levels were similar in AL-CA and ATTR-CA (1462 vs. 1363 pg/mL). Apical sparing pattern was common and did not differ between groups. LCD was more frequent and prolonged in patients with AL compared to ATTR, with a duration of 75 msec in AL-CA vs. 9 msec in ATTR-CA. Median duration of systolic diastasis in AL patients was 28 vs. 11 msec in ATTR-CA (p = .03) and relaxation was 28 vs 5 msec, respectively.
Conclusion: Patients with AL amyloid cardiomyopathy often have longitudinal contractile diastasis measured by LS; this is uncommon in ATTR-CA. Apical sparing is equally prevalent in both types, suggesting that LCD is an independent contraction abnormality. This may reflect a specific myocyte abnormality in AL-CA rather than just the effect of amyloid infiltration.
Abstract
Topic: Basic Science AL
Immunoglobulin light chain (AL) amyloidosis is caused by clonal B or plasma cells proliferating in the bone marrow that produce monoclonal immunoglobulin proteins that misfold and aggregate in tissues. While AL plasma cells share cytogenetic aberrations with plasma cells from multiple myeloma, their transcriptome and immune bone marrow microenvironment (BME) composition are not well characterized. Here, we collected serial BM aspirates from six AL amyloidosis patients, healthy donors and other plasma cell disorders and performed single-cell RNA-seq combined with CITE-seq and TCR sequencing to characterize AL plasma cells and the immune BME before and after daratumumab based therapy. Compared to non-AL plasma cells, AL plasma cells were featured by differentially expressed genes related to the presence of t(11;14) such as CCND1, but also by genes not previously reported such as Integral Membrane Protein 2B (ITM2B), which is known to be involved in beta-amyloid processing, and others that may constitute novel therapeutic targets. Gene set enrichment analysis revealed differential activity of essential cellular pathways including mainly endoplasmic reticulum associated protein degradation, protein transportation and apoptosis. Compared to other plasma cell disorders at diagnosis, AL BME had more cellular diversity, higher CD8 memory T cells levels and CD68+ monocytes with significant deregulation of IL-1β pathway. Hematologic and organ response following daratumumab therapy were associated with further increase in CD8+ memory T cells level and T cell clonotype selection along with persistent monocytes alterations, highlighting the role of the immune BME in AL amyloidosis pathogenesis and response to treatment.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: 124I-evuzamitide (AT-01) is a novel pan-amyloid PET radiotracer that is renally excreted and undergoes rapid dehalogenation of unbound tracer, allowing amyloid-bound tracer imaging. Using a mixed patient cohort of light chain amyloidosis (AL), transthyretin amyloid cardiomyopathy (ATTR-CM), and a control population, we sought to characterize renal involvement through 124I-evuzamitide imaging.
Methods: Renal AL amyloidosis was diagnosed by standard clinical, laboratory, biopsy, and imaging criteria. All subjects underwent PET/MRI with 124I-evuzamitide, and uptake was quantified using renal standardized uptake value ratio (SUVR, ratio of renal parenchymal SUV/left ventricular blood pool SUV).
Results: We enrolled 50 patients (mean age: 72 ± 9.1 years, 74% male). Of those, nine (18%) had clinically diagnosed renal AL amyloidosis. In one patient with renal AL amyloidosis requiring kidney transplant, SUVR of the native AL-affected kidneys was 12.8 with diffuse homogenous uptake, compared to an SUVR of 0.9 in the unaffected transplanted kidney, Figure 1A. Median 124I-evuzamitide renal SUVR in those with renal AL amyloidosis was 2.1 (1.4, 4.8) compared to 1.0 (0.8, 1.4) in those without (p < .0001), Figure 1B. Homogenous kidney uptake was consistently seen in patients with renal AL amyloidosis, while a heterogenous pattern was seen in others. Further analyses are ongoing.
Conclusion: Renal AL amyloidosis can be imaged utilizing 124I-evuzamitide PET/MRI. This study provides compelling evidence of 124I-evuzamitide radiotracer specificity in renal AL amyloidosis. Future work is needed to define diagnostic thresholds in a large cohort utilizing histopathological correlation to validate 124I-evuzamitide performance.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: While amyloid fibrils cause kidney disease in light chain amyloidosis (AL), it remains unclear if worsening kidney function in transthyretin amyloid cardiomyopathy (ATTR-CM) is related to amyloid fibril infiltration or progressive cardiomyopathy. 124I-evuzamitide (AT-01), a novel pan-amyloid PET radiotracer, allows for cardiac and renal assessment of amyloid deposition.
Methods: Cardiac (AL and ATTR) amyloidosis and renal AL amyloidosis were diagnosed by standard clinical, laboratory, biopsy, and imaging criteria. All subjects underwent PET/MRI with 124I-evuzamitide. Uptake was quantified using standardized uptake value ratio (SUVR, ratio of organ SUV/left ventricular (LV) blood pool SUV). Estimated glomerular filtration rate (eGFR) was measured immediately prior to tracer injection.
Results: We enrolled 50 patients (mean age: 72 ± 9.1 years, 74% male, 56% ATTR, 24% AL, 20% control, 68% cardiac amyloidosis, 18% renal AL amyloidosis). Median 124I-evuzamitide LV SUVR in cardiac amyloidosis was 1.8 (1.7, 1.9) compared to 1.0 (0.9, 1.2) in those without. Median renal 124I-evuzamitide SUVR was 0.9 (0.8, 1.0) in ATTR-CM. Patients with ATTR-CM did not have the diffuse renal 124I-evuzamitide uptake seen in patients with renal AL amyloidosis. In patients with ATTR-CM, 50% had an eGFR <45 mL/min/m2 (mean: 48 ± 12.4 mL/min/m2). eGFR did not correlate with renal 124I-evuzamitide uptake in patients with ATTR-CM (r = 0.04, p = .855), while it did correlate with LV wall thickness (r = −0.57, p = .001) and LV mass (r = −0.54, p = .002).
Conclusion: Renal dysfunction in patients with ATTR-CM may be related to worsening cardiomyopathy rather than renal amyloid fibril deposition. Further studies correlating 124I-evuzamitide imaging with histopathological findings are necessary.
Abstract
Topic: Diagnosis AL
Local AL amyloidosis (locAL) is a locally produced light chain (LC) deposit disorder at a single anatomic site, forming tumor-like amyloid lesions. The lung, bladder, larynx, and skin are the most commonly involved. Although no difference is known in progression-free survival (PFS) among organs, patients with identified clonal infiltrations at the amyloid deposition site are known to have a short PFS. We present a case of a 71-year-old man with a skin locAL, who underwent skin excision operations 8 times. His first nasal skin nodule was diagnosed as hemangioma and was Congo red (CR)-negative. In the same anatomic region, the second nodule emerged and was partially accompanied by CR-positive structureless depositions. From the third lesion onwards, the CR-positive sites were immunohistochemically λ-positive, and many λ-positive plasma cells with swollen cytoplasm were observed. Since the sixth lesion, lymphoplasmacytic infiltrations composed of multinuclear giant cells (MGC) surrounded by λ-positive plasma cells appeared. By immunohistochemical and proteomic analysis, we have detected two sublayers of the plasma cells: a sublayer that overexpresses λ-LC mRNA and a sublayer with heavy λ-LC protein deposition. These lymphoplasmacytic infiltrations are tightly surrounded by cell-size granular amyloid deposits, which are serum amyloid P positive. From this case, we hypothesize that the interaction between MGCs and plasma cells triggers the overexpression of the λ-LC mRNA and the production of amyloid precursor proteins, which leads to the apoptosis of the plasma cells. The amyloid precursor proteins are speculated to accelerate the amyloid accumulation process as seeds.
Abstract
Topic: Diagnosis ATTRv
Introduction: Although characterized as a Portuguese descent country, the Brazilian population is multi racial, including mainly Portuguese and African descents, but also Italians, Spanish, Japanese, Germans, and Dutch, with minor contribution of other countries. Due to the huge Portuguese importance, the TTRVal50Met was thought to be the only mutation, but this concept gradually changed. In this study we characterized the distribution of ATTRv in Brazil and its ethnical aspects.
Methods: This cohort was descriptive, retrospective, and enrolled a group of patients harboring suggestive phenotypes and at-risk family members of index cases with the TTR pathogenic mutation from 19 Brazilian centers.
Results: We enrolled a total of 784 patients belonging to 261 families. 385 (49.1%) were male. The disease was manifest in 435 (55.5%) of patients and one third (33.3%) were asymptomatic carriers (11.2% unknown). The three most frequent TTR mutation were TTRpVal50Met (53.6%), TTRpVal142Ile (31.6%) and TTRIle127Val (8.4%). Other 13 mutations account for equal or less than 1% (Ala60Thr, Arg123His, Asp58Ala, Asp58Tyr, Glu109Lys, Glu112Lys, Ile88Leu, Phe64Ser, Phe84Leu, Pro44Ser, Pro791Ser, Thr80Ala, Val91Ala). The distribution by ethnicities showed that 378 (48,2%) patients identified themselves as white, 306 (39%) as mixed, 72 (9.2%) as black and 5 (0.6%) as Asiatic (2.9% unknown).
Conclusion: Our data highlights the importance to suspect of ATTRv in patients with suggestive symptoms and signs, regardless of ethnicity. We also call attention to the epidemiological importance of the TTRVal142Ile and the TTRIleVal variants in the Brazilian population and to the large variety of TTR mutations causing this disease.
Abstract
Topic: Diagnosis ATTRwt
Project approved and supported by Pfizer, within the Global Bridges at Mayo Clinic and Pfizer Global Medical Grants – Request for Quality Improvement Proposals (RFP): Raise awareness and promote timely diagnosis of TTR amyloidosis (Asia, Latin America, Africa, and the Middle East).
Background: The lack of knowledge about amyloidosis among medical graduates and their teachers contributes to the patient's long journey to diagnosis, particularly in primary health care.
Objective: Expand knowledge of transthyretin amyloidosis for primary care medicine teachers and medical interns.
Methods: a course on amyloidosis was held for 5th and 6th year internship students and their teachers, during the internship in primary health care. All students took an initial pre-test (grade ranging from 0 to 10), containing 5 areas of knowledge: pathophysiology and epidemiology, clinical picture, complementary exams, diagnosis, and treatment. At the end, a post-test was applied to analyze the degree of knowledge improvement.
Results: 325 students and teachers participated in the course, 225 in person and 100 online. In the face-to-face group, the overall average score in pre-test was 5.9 (±1.27), in students group 5.94 (±1.25) and in teachers group 5.78 (±0.31). In the post-test, the average overall grade was 9.05 (±0.9), 9.04 in students group and 9.58 in the group of teachers. In the initial assessment, a higher error rate was observed regarding treatment (54.5%), and the lowest in pathophysiology (35%). The improvement in grades after the course was greater in the treatment, with an increase of 102.6% (from 45.5% to 92.1%), followed by clinical condition (74.5%), pathophysiology (53.8%), exams (43.3%) and diagnosis (39.8%).
Conclusion: There is a high level of lack of knowledge about the amyloidosis, but considerable improvement could be seen with simple training. The dissemination of knowledge continues to be the main foundation for shortening the patient's journey.
Abstract
Topic: Diversity Equity Inclusion
Introduction: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy that disproportionately affects African Americans in the United States. Hereditary transthyretin CA clusters by race and geography worldwide but few studies have evaluated epidemiological trends in Asian and Native Hawaiian or Pacific Islander (NHOPI) populations. We sought to determine the demographics of CA in Hawaii’s majority-minority population.
Methods: This is a retrospective cross-sectional study of patients diagnosed with CA between January 2019 and December 2023 at a tertiary cardiovascular center in Hawaii. Serum and urine protein electrophoresis, free light chains and immunofixation, and bone scintigraphy were utilized to differentiate between transthyretin (ATTR) and light chain amyloidosis (AL)
Results: A total 64 patients (34.4% Whites, 45.3% Asians, 15.6% NHOPI, 4.7% Blacks) were diagnosed with CA with an average age of 78.4 ± 10.1 years. Of that, 46 (71.9%) were male, 58 (90.6%) had ATTR, and six (9.4%) had AL. Nine NHOPI patients had ATTR without genetic mutations. Amongst Asians, 25 had ATTR and one Japanese patient had a V50M mutation. 21 white patients had ATTR without genetic mutations. Two Black patients had ATTR amyloidosis, and both had the V142I mutation. Three ATTR patients and one AL patient received heart and bone marrow transplant.
Conclusion: This study is one of the first to evaluate CA demographics amongst Hawaii’s majority-minority population. Although our data for White and Black patients follow national trends, no mutations were identified in NHOPI’s. Larger studies are needed to evaluate the disease burden of hereditary ATTR amongst NHOPI and Asian patients in Hawaii.
Abstract
Topic: Imaging
Subtopic: Radionuclides
[18F]-Florbetaben positron emission tomography (F-PET) emerged as a promising non-invasive tool to identify and quantify cardiac involvement in AL amyloidosis and possibly discriminating it from ATTR amyloidosis or other mimicking cardiomyopathies. The MoRBiDA trial (NCT-04392960) evaluates cardiac imaging through echocardiography, magnetic resonance (MRI) and F-PET in treatment-naïve patients with AL amyloidosis at diagnosis and 6-months from treatment initiation. Here we report the first analysis of MoRBiDA, focusing on the diagnostic performance of F-PET.
A 3-dimensional list-mode dynamic 50 min PET acquisition of the heart started immediately after injection of a mean dose 376 (± 70 SD) MBq of florbetaben. Semi-quantitative PET parameters (SUVmean, SUVmax, Myocardial Tracer Retention) of cardiac walls were evaluated at 15/50/110 min after tracer administration.
Twenty-eight patients with biopsy proven AL amyloidosis and elevated NT-proBNP were enrolled. In 3 cases echocardiography, MRI and F-PET were not suggestive for AL cardiac amyloidosis while cardiac biomarkers were elevated due to previous ischemic heart disease. In 24 (86%) patients, heart involvement was confirmed by cardiac biomarkers, MRI, and echocardiography. In 21 of these subjects F-PET was also consistent with heart involvement. In the remaining 4 patients with confirmed heart involvement by echocardiography and MRI, F-PET did not show a delayed uptake compatible with AL amyloidosis (Table).
Delayed F-PET uptake can be absent in patients with AL amyloidosis and early (stage II) heart involvement. Our results suggest caution before introducing this tracer in the diagnostic workup. The role of F-PET to monitor amyloid deposits is being assessed in the MoRBiDA trial.
Abstract
Topic: Imaging
Subtopic: MRI
Background: Light chain amyloidosis (AL) with advanced cardiomyopathy (CM) portends a prognosis of less than 6 months if untreated. The ANDROMEDA trial significantly improved outcomes but relies on diagnosis and accurate organ staging. Standard cardiac staging is limited by test sensitivity, particularly in early disease. Cardiac magnetic resonance (CMR) offers high resolution morphologic assessment and detailed tissue characterisation which is highly sensitive and specific for amyloidosis and holds promise for early diagnosis. CMR is not routine but recommended when echocardiography (TTE) is suggestive or other pathology suspected. We present a case series utilising CMR for early AL-CM diagnosis when other modalities were non-diagnostic.
Methods: All patients between 2022 and 2024 referred to St Vincent’s Amyloid multi-disciplinary team with suspected or confirmed AL who underwent CMR for clinical suspicion of cardiac disease were evaluated. Clinical suspicion was defined as unexplained symptoms (fatigue, breathlessness, or oedema) or biomarker elevation, despite prior non-diagnostic cardiac imaging.
Results: Six clinically suspicious cases underwent CMR with all demonstrating AL-CM. All TTE's showed left ventricular (LV) ejection fraction and strain within normal parameters. TTE LV wall thickness was normal in four. Only two patients had suspicious symptoms, but all had mildly elevated NT-proBNP. CMR in all demonstrated patchy late gadolinium enhancement without inflammation (normal T2) but increased extracellular volume(T1) and pericardial effusions. Diagnosis was confirmed via biopsy (3 endomyocardial, 1 pericardial, 1 renal, 1 bone-marrow). CMR altered diagnosis and treatment in three cases.
Conclusions: CMR holds promise in enhancing AL-CM diagnostic accuracy and early recognition, ultimately facilitating clinical decisions, and improving care. Further studies of routine CMR use are required.
Copyright for this individual abstract is: © 2024 Copyright of the Crown in Australia. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Abstract
Topic: Organ Transplant
Background: Abnormal protein fibril deposition in amyloid cardiomyopathy (CM) results in restrictive physiology, typically presenting as heart failure (HF). This is most commonly due transthyretin (ATTR) deposition, from pathogenic genetic variants (ATTRv) or abnormal protein folding (ATTRwt). Prognosis remains poor, typically less than 4 years and heart transplantation (HT) remains the only definitive advanced HF treatment. HT has been underutilised in ATTR-CM, particularly ATTRwt, due to patient factors; traditionally poor outcomes, comorbidities and age, and systemic factors; late diagnosis, under-recognition of severity and waitlist times. Waitlist changes and improving outcomes mean HT is an increasing therapeutic option. We review our ATTR-CM HT outcomes over time.
Methods: Patients with ATTR-CM who underwent HT at St Vincent’s Hospital with between January 2010 and 2024 were studied.
Results: Five patients with ATTR-CM underwent HT. All were diagnosed pre-transplant, male, NYHA III with a median age 66 years (range 59–71). Genetic assessment identified one pathogenic variant (TTRp.Val40Ile), others were ATTRwt. Three patients were Gilmore Stage II. Mean left ventricular ejection fraction was 44% but cardiac index was very low, 1.7 L/min/m2. None required mechanical bridge-to-transplantation. Four were transplanted since 2019, all were alive at 1-year and median survival was 3.63 years. Three deaths, from chronic renal failure requiring hemodialysis, metastatic melanoma, and COVID-19, occurred respectively. ATTR-CM did not recur on routine follow-up. Autonomic neuropathy occurred post-HT in two, with no documented end organ extra-cardiac manifestations prior.
Conclusions: Although larger numbers and longer follow-up is required, HT has reasonable short-to-medium term outcomes in a small ATTR-CM cohort, especially ATTRwt. Despite historical underutilisation, HT is a growing option in the evolving ATTR-CM management landscape.
Copyright for this individual abstract is: © 2024 Copyright of the Crown in Australia. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Abstract
Topic: Basic Science ATTR
Transthyretin (TTR)-related amyloidosis (ATTR) is a systemic disease characterized by the accumulation of TTR in insoluble amyloid fibers. ATTR is a progressive and ultimately fatal disease, with approximately 130 mutations associated with the rare inherited forms of the disease. The predominant manifestations are typically polyneuropathic or cardiac, with an average age of onset of 39 years. Different mutations lead to different phenotypes and varying degrees of disease severity.
This research focuses on two amyloidogenic variants, Val122Ile (V122I) and Ser52Pro (S52P), compared to wild-type TTR (WT-TTR) and the protective form T119M. V122I is associated with late-onset cardiomyopathy, while S52P is associated with early-onset aggressive polyneuropathy with subsequent cardiomyopathy. Although all variants were subjected to structural characterization using X-rays, no significant differences to WT-TTR were found.
To further investigate the structural aspects and dynamics of the protein, in particular the fast and slow movements and the population of the different conformers, nuclear magnetic resonance (NMR) is used in this study. In addition, the effect of stabilizers in different variants is also addressed. NMR provides unique insights into these structural details and helps to understand the different pathological outcomes, both in terms of prognosis and organ involvement.
Abstract
Topic: Basic Science ATTR
Transthyretin (TTR) amyloidosis is a degenerative and fatal disease characterised by the accumulation of amyloid leading to organ damage.
In a previous study, we used NMR spectroscopy to describe the TTR long-distance conformational effects induced in buffer solution by the binding of the ligands tafamidis and mds84. Mds84 is a bivalent ligand capable of binding TTR by occupying both binding sites and the connecting channel and inhibiting fibril formation. We have also shown that occupancy of the first site by tafamidis is followed by a rearrangement of the second binding site involving residues at the dimer interface and at the outer TTR surface not in contact with the ligand. Simultaneous occupancy of TTR thyroxine binding pockets could overcome the limitation of monovalent ligands possibly due to negative cooperativity.
However, our and other studies in buffer do not consider the crowded environment in blood and ignore, for example, the different diffusion properties in different media, which are crucial for the interactions between molecules. In addition, the complex mixture of molecules in blood may affect the binding of ligands like tafamidis, AG10 and mds84 to TTR and in particular the second binding site, which is characterised by a weaker binding affinity for monovalent ligands. In this study, we show by NMR directly in human serum that the TTR overall structure is similar to the one in buffer, that bivalent paramagnetic cations bind to TTR and we also determine ligand/TTR ratio needed to obtain full occupancy of both binding pockets.
Abstract
Topic: Prognosis AL
Background: AL patients present sustained paradoxical vasodilation in response to sympathetic stimulation by cold pressor test (CPT). The clinical relevance of this finding is unknown.
Purpose: We investigated the association between CPT-induced vascular and hemodynamic responses with clinical characteristics in patients with AL amyloidosis.
Methods: We consecutively recruited 113 newly diagnosed patients with AL amyloidosis before treatment initiation. High resolution ultrasonography was used to measure the maximum vasodilation of the brachial artery in response to a cold stimulus and 3 min after its withdrawal. Percent Systolic (SBP%pCPT) and diastolic blood pressure (DBP%pCPT) change after cold stimulus were measured at the same timepoints. Clinical and laboratory makers of autonomic dysfunction were also measured in a subgroup of the population. All-cause and cardiovascular mortality were defined as endpoints of the study.
Results: Sustained vasodilation post CPT (%pCPT) was associated with markers of autonomic dysfunction, namely dipping status (p < .05) and sudomotor dysfunction (p = .064) and with NYHA stage, baseline NTproBNP and heart failure (p < .05 for all). DBP%pCPT was associated with the neuropathy symptom scale (NSS Autonomous, p = .032), while SBP%pCPT was inversely associated with Mayo stage. Vasodilation%pCPT was independently associated with cardiovascular death (adjusted HR =1.154, p = .017) while both DBP%pCPT (HR =0.955, p = .027) and SBP%pCPT (HR =0.947, p = .04) were independently associated with all cause death (adjusted for the core model including age, sex, SBP, Mayo stage and nerve involvement).
Conclusions: In AL amyloidosis, sustained paradoxical vasodilation and decreased SBP and DBP in response to sympathetic stimulation were associated with autonomic dysfunction, advanced cardiac involvement, and poor survival.
Abstract
Topic: Basic Science ATTR
Amyloidosis is triggered by the truncation of amyloid precursor proteins, causing organ damage. While previous studies have found that the truncation of amyloid A (AA) and amyloid transthyretin (ATTR) occurs at the C- and N-terminals respectively, the detailed mechanism of fibril formation remains unclear. Liquid chromatography mass spectrometry can be used for qualitative purposes, but quantification of tryptic peptide residues is difficult. Therefore, we employed a mass spectrometry-based quantification by isotope-labeled cell-free (MS-QBIC) method to analyze the truncation processes in amyloid fibrillogenesis of AA and ATTR using the formalin-fixed paraffin-embedded tissues of autopsy cases. Native serum AA (SAA), which consists of 104 amino acids, adopts a fold stabilized by its long C-terminal tail. Using MS-QBIC, the N-terminals were detected in all AA samples, whereas the C-terminals were almost absent or may be present in minimal amounts in amyloid deposits. In ATTR, the process of transthyretin (TTR) transitioning from an ‘early fibril state’ with full-length ATTR to a ‘mature fibril state’ with a truncated low-amyloidogenic segment has been mathematically revealed. The amount of full-length ATTR in the early state was found to be nine times higher than that in mature state. The relationship between the early-to-mature ratio and clinical features is unknown, but large cohort studies using MS-QBIC may shed light on the clinical significance of the amyloid fibril states. A possible mechanism for the fibril formation for both AA and ATTR depends on the activities of an endogenous proteases in the background.
This abstract is based on a previously published paper. Please see Shintani-Domoto Y (*Corresponding author), Ode L. K, Nomura S, Abe H, Ueda R. H, Sakatani T, Ohashi R. Elucidation of the mechanism of amyloid A and transthyretin formation using mass spectrometry-based absolute quantification. Virchows Archiv. 2023; Jul 15. doi: 10.1007/s00428-023-03591-w.
Abstract
Topic: Prognosis AL
Stem cell transplant-related mortality (TRM) decreased owing to improvements in patient selection. New therapeutic options challenge the utilization of autologous stem cell transplantation (ASCT) in AL amyloidosis. Combining functional and organ impairment measures into a predictive scoring model can improve patient selection and reduce TRM.
AL amyloidosis patients (n = 1718) transplanted between 2003 and 2020 from 9 centers were included. Pre-ASCT organ function data were obtained. A random forest (RF) classifier with 10-fold cross-validation was used for variable selection. The final model was fitted using logistic regression.
The median age was 59. The most involved organs were kidney (69%) and heart (52%). Mayo 2004 stage I-II was present in 83% of patients. 54% of patients received Induction. Seventy-five patients (4.4%) died within 100 days of transplant. Ten factors were predictive for day-100 TRM on univariate analysis with an odds ratio (OR) of 1.99–3.93 (). RF classifier using all these variables created a model with an area under the curve (AUC) of 0.69 ± 0.13. Using SHAP function to refine the model selection, a 6-variable model was built with an AUC of 0.7 ± 0.13. The following variables are included in the final model: NT-proBNP/BNP, serum albumin, ECOG score, dFLC, cDLCO, and systolic blood pressure. With 1 point for each variable, the 3-month TRM was 1.5%, 3.7%, 4.9%, and 18.4% for 0, 1, 2, >2 points, respectively.
Table 1. Univariate and multivariate logistic regression models.
We created a model to predict TRM in AL amyloidosis undergoing ASCT. The included domains reflect the heterogeneity of this disease and the various causes of TRM among patients.
Abstract
Topic: Diagnosis AL
Background: Mass spectrometry-based proteomics (MS) has become the method of choice for the detection of amyloidogenic protein in a quantitative manner in organ biopsies and fat aspirates. MS does not only identify the subtype-specific protein but also measures an amyloid protein signature that is shared across all amyloidosis subtypes in various tissues. An amyloid positive biopsy from suspected involved organ is diagnostic but it is also an invasive procedure with some risk of complication. In contrast, fat aspirate is a minimal invasive procedure and has been shown to be a fairly sensitive screening for systemic amyloidosis.
Objective: We developed a method for sample preparation of amyloid plaques isolated from fat aspirates by laser microdissection (LMD) followed by the identification of the amyloidogenic proteins using ultra-sensitive MS-based proteomics.
Results: LMD-MS significantly improved the detection of amyloidogenic proteins over background proteins, especially in fat aspirates that showed weak staining with Congo Red. Moreover, total analysis time was kept below 3 h. Using this protocol we retrospectively and successfully subtyped fat aspirates collected from patients suspected with systemic amyloidosis, including biopsies that showed weak CR staining, and where subtyping using existing MS-based methods have been unsuccessfully.
Summary and conclusion: A novel ultra-sensitive LMD-MS-based method for amyloid subtyping of CR positive fat aspirates was developed. Using this method, we were able to subtype fat aspirates with low amounts of amyloid plaques, which it has not been possible to subtype using MS-based methods used so far, even without sacrificing total analysis time.
Abstract
Topic: Diagnosis AL
Background: Light chain (AL) stands out as one of the prevalent and severe forms of amyloidosis causing significant damage to vital organs. This report empathizes an evolution of localized to systemic AL amyloidosis.
Clinical Case: A 58-year-old man, previously healthy, evolved with progressive fatigue for 2 years and refractory symptoms of upper airway. Computed tomography of the face and neck showed diffuse and noduli form thickening of the true and vestibular vocal folds with minute calcifications on the right and in the anterior commissure, the left vestibular fold and in the left half of the epiglottis and of tubal torus. Hemogram and renal function within normal limits, free light kappa 20.57 mg/L and free light lambda 8.05 mg/L and k/L 2.56. Electroneuromyography with focal neuropathy in the bilateral carpal tunnel and 2 years later, axonal, and distal sensory-motor neuropathy. Lumbosacral spine with degenerative changes, thickening of the yellow ligaments and reduction of the spinal head, and partial diffuse reduction of the spinal canal. Myocardial resonance with normal measurements, faint late enhancement of a non-ischemic pattern in the basal infero-lateral segment of the left ventricle. Subacute vascular injury already documented. He underwent otorhinolaryngological surgery with local scraping, Congo-red was positive under polarized light and mass spectrometry confirmed light chains. Radiotherapy was performed and upon recurrence within 6 months and systemic signs, he was referred to the DARA-VCD protocol by hematology.
Conclusion: This case report was a tracheal involvement of AL amyloidosis but evolving over the years to possible systemic signs of the disease under investigation.
Abstract
Topic: Diversity Equity Inclusion
Background: Women with heart failure report worse symptom severity and depressed mood. Currently, there are no data about gender differences in patient reported outcomes in ATTR-CM.
Methods: This is a cross sectional study of patients with ATTR-CM presenting in Columbia University Medical Center from 2008 to 2023 and the Kansas City Cardiomyopathy Questionnaire (KCCQ) was recorded. Continuous data are presented as median and interquartile range (IQR).
Results: Thirty-three females (19 wild-type, 14 variant) and 253 males (208 wild-type, 45 variant) were recruited (Table). The time of KCCQ completion from diagnosis was 14 (IQR: 3–36) months for males and 15 (IQR: 5 -27) for females (p = .82). Overall, women had lower KCCQ score (70 vs 82, p = .034). Women with wild- type disease presented lower KCCQ (68 vs 83, p = .017), but they were more often NYHA class III (58% vs 29%). Also, women with V122I (N = 8) variant presented lower KCCQ (61 vs 72), although not significant. In addition, women in NYHA III, presented significantly worse KCCQ, (52 vs 65, p = .045). In univariable regression analysis, female gender was associated with lower KCCQ (mean difference: -8.4 points, p = .03). However, after adjustment for age, genotype, time from diagnosis and NYHA class, female gender was not associated with KCCQ score.
Conclusions: Female gender is not independently associated with worse patient reported health status in ATTR-CM. However, women present with more advanced phenotype and thus worse reported outcomes, suggesting a delay in the diagnosis of ATTR-CM.
Abstract
Topic: Diagnosis ATTRwt
Transthyretin cardiac amyloidosis is often preceded by carpal tunnel syndrome (CTS) by 5–9 years. CTS biopsy could perhaps be useful for monitoring patients with amyloidosis for early diagnosis of cardiac involvement. Systematic biopsy seems hardly feasible. We report here the largest series of amyloidosis in the CTS and compare patients with and without amyloidosis to determine the demographic and surgical characteristics associated with amyloidosis.
This was a retrospective, single-center, case-control study comparing patients with and without amyloidosis who underwent CTS surgery between 2000 and 2020. Adult patients with ≥1 CC biopsy were included.
8816 patients were included. Amyloid deposits were found in 853 (9.7%). Patients with amyloidosis were more often male (47.4% vs. 32.8%, p < .001), older (77.9 years vs. 53.2 years, p < .001) had more bilateral surgeries (50.2% vs. 37.1%, p < .001) and more left surgeries in case of unilateral operations (p < .05). Compared with mild deposits (88.4%), patients with non-mild deposits (11.6%) were more often male (61.3% vs. 46.1%, p < .05) and had more bilateral amyloidosis in the case of bilateral biopsies (64.0% vs. 36.4%, p < .001). Table 1 shows the prevalence of amyloidosis according to age, sex and laterality of surgery.
This study confirmed well-known characteristics of amyloidosis: it affects older men in particular and is associated with bilateral surgeries. Patients with non-mild deposits were at risk of bilateral amyloidosis deposits when surgery was bilateral. The main weakness of this study is the absence of typing, although the literature reports a large majority of transthyretin amyloidosis.
Abstract
Topic: Diagnosis ATTRwt
Cardiac amyloidosis (CA) is often preceded by carpal tunnel syndrome (CTS). Screening for CA in patients undergoing CTS surgery may enable early diagnosis. The high incidence of CTS makes systematic screening impossible. The aims of this study were to identify risk factors for scintigraphic CA after CTS surgery, and in patients with CTS amyloidosis.
This single-center retrospective study compared characteristics of patients with Perugini 2–3, Perugini 1 and Perugini 0 scintigraphies. We included patients with ≥1 CTS surgery, CTS biopsy, Congo red staining, and ≥1 whole-body bone scintigraphy (WBS). We excluded those with WBS >2 years before/>15 years after CTS surgery. WBS were reviewed by 2 nuclearists.
21 Perugini 2–3, 13 Perugini 1, and 261 Perugini 0 were included. The proportion of men, bilateral surgeries were comparable in the 3 groups. Patients ≥ Perugini 1 were older (p < .001), and more often had amyloidosis in the CTS (p < .001). There appeared to be a dose effect of amyloid deposits: the association was stronger for non-mild than for mild deposits, with ORs of 20.5 [5.2–80.5] and 12.4 [3.2–47.5] respectively. In CTS amyloidosis patients, the risk factors for Perugini 2–3 were age >80 years (OR 4.5 [1.5–13.2]), surgery-WBS delay >5 years (OR 3.8 [1.2–12.0]) and non-mild amyloid deposits (OR 5.7 [1.4–23.6]).
CTS amyloidosis and age >80 years at WBS were associated with Perugini 2–3. In the case of CTS amyloidosis, non-mild deposits, >80 years, and CTS-WBS delay >5 years were the main risk factors. Biopsy of patients undergoing CTS surgery could be interesting to target patients at risk of CA.
Abstract
Topic: Basic Science AL
N-glycosylation of monoclonal light chains (LCs) is a risk factor for MGUS progression, particularly towards AL amyloidosis. We have recently reported that N-glycosylation of κ clonal LCs within the DE loop of framework region 3 (FR3-DE) is significantly associated with AL amyloidosis. This observation might refine current amyloidogenicity prediction tools, possibly facilitating early diagnosis.
Having encountered rare cases where the widely employed prediction tool NetNGlyc failed to detect an N-glycosylation site, we benchmarked available N-glycosylation prediction tools for their ability to identify N-glycosylation in clonal LCs.
Through systematic research, we identified all currently available, sequence-based N-glycosylation prediction tools (n = 7). We analyzed a cohort of 147 patients with monoclonal gammopathy (n = 123 AL, n = 1 MGUS, n = 23 MM): clonal LCs were sequenced through SMaRT M-Seq, N-glycosylation was predicted in silico with all available tools and the N-glycosylation status was verified biochemically through Western blotting on urine samples.
Overall, N-glycosylation prediction accuracy ranged from 95.2% to 98.6%, with 4 tools displaying the highest accuracy level.
Then, using published and new AL and non-AL clonal κ LC sequences and considering the presence of an N-glycosylation site anywhere or within FR3-DE as a risk factor for AL, we confirmed that the spatial knowledge of the putative N-glycosylation site significantly increases the ability to detect amyloidogenic LCs, in terms of positive predictive value and Matthew Correlation Coefficient.
Overall, these data reinforce the notion that the N-glycosylation hotspot of clonal κ LCs is associated with AL amyloidosis and could help identifying pathogenic LCs through sequence-based prediction tools.
Abstract
Topic: Basic Science AL
In patients with monoclonal gammopathies (MGs), M proteins are patient-unique, can cause potentially fatal organ damage and be used for personalized tumor tracking. The presence of circulating tumor cells may provide a window of opportunity to sequence patients’ specific M protein genes in the peripheral blood (PB).
PB-MNCs were subjected to SMaRT M-Seq to obtain the circulating repertoire of the involved light chain (LC) isotype in a cohort of patients with MGUS (n = 2), AL amyloidosis (n = 37), and MM (n = 41). Mass spectrometry (MS) analysis of urinary peptides was performed to identify/validate the clonal LC sequence from the circulating repertoire. SMaRT M-Seq on matched bone marrow (BM) samples to identify the bona fide clonal LC sequence was performed for confirmatory purposes.
Reads with 100% identity to the bona fide clonal LC were identified in the PB of 78 patients (98%) and were the dominant sequence in 67 cases (86%). In all cases where the most abundant, discrete clonal sequence represented >15% of all reads detected within the PB (n = 53, 66%), such sequence invariably coincided with the bona fide clonal LC sequence. In the remaining 27 patients, mass spectrometry-based analysis of the urinary proteome and mapping of tryptic digestion peptides against each pt’s circulating repertoire, identified the bone fide clonal LC sequence in all but 4 cases.
Our SMaRT M-Seq liquid biopsy approach enables the identification of the full-length clonal LC sequence in virtually all patients with MGs, paving the way for NGS and/or MS-based personalized tumor tracking and minimal residual disease assessment.
Abstract
Topic: Treatments of ATTR
Introduction: Patisiran, a small interfering RNA, improves neuropathy and cardiac parameters in hereditary ATTR (ATTRv) amyloidosis. Reductions in extracellular volume by cardiac magnetic resonance imaging and cardiac tracer uptake on bone scintigraphy in patients receiving patisiran suggest amyloid regression. However, evidence confirming amyloid regression in tissue is lacking.
Methods: All ATTRv amyloidosis patients on patisiran treatment at the University Medical Center of Groningen, the Netherlands, were evaluated for eligibility in a retrospective cohort study. Subcutaneous abdominal fat tissue aspirates were stained with Congo red as part of routine care. Congo red (CR) scores (0–4+) before and after patisiran initiation were extracted from the patient files and compared using the Wilcoxon signed-rank sum test. Patients without baseline or follow-up aspirates were excluded.
Results: Thirty-six of the 64 ATTRv amyloidosis patients on patisiran were included. Median serum transthyretin reduction was 82%. Prior to initiation of patisiran, CR-score increased in 50% and decreased in 19% of patients (p = .070). Within the first year of treatment with patisiran, CR-score increased in 18% and decreased in 27% of patients (p = .439). Between year one and two, CR-score increased in 8% and decreased in 69% of patients (p = .011). After 2 years of treatment, CR-score increased in 13% and decreased in 56% of patients compared to baseline (p = .029). See Figure 1.
Discussion: This is the first study to provide evidence of regression of amyloid in tissue of ATTRv amyloidosis patients treated with gene-silencing therapy, demonstrating a decrease in CR-scores after 2 years of treatment with patisiran.
Abstract
Topic: Prognosis AL
IgM-AL amyloidosis is a rare distinct entity, characterized by clonal heterogeneity. Although several retrospectives identified prognostic factors, some questions remained unanswered, as the prognostic role of dFLC and IgM concentration at diagnosis and after treatment. Patients with IgM-AL amyloidosis evaluated at the at the Heidelberg Amyloidosis Center between May 2003-December 2019 were included in the study. Multivariable analysis was performed to identify prognostic factors for overall survival (OS) and hematologic progression-free survival (hemEFS). One-hundred patients were included in the study. The B-cell clone showed a lymphoid immunophenotype (lymphC) in 64% and plasma cellular (pcC) in 28% cases. Sixteen patients received chemotherapy for the underlying clonal disease before diagnosis of AL amyloidosis. Median OS and hemEFS were 42 and 15 months. On multivariable analysis (Table 1), dFLC(log10) was prognostic for OS (HR 2.51, p < .001) and hemEFS (HR 2.04, p = .002), while IgM concentration showed just a trend for worse hemEFS (HR 1.02, p = .056). Severity of heart involvement, assessed by European Mayo stage, was confirmed prognostic for OS (overall p = .004). After first-line treatment (rituximab-based in 72% of lymphC and 8% of pcC), hematologic response, assessed both by reduction in dFLC and IgM concentration, resulted in better OS. However, patients who achieved an IgM-response but not a dFLC-response had a shorter OS compared to those with a response also according to dFLC (n = 16, median 14 months vs. not reached; p = .009). In IgM-AL amyloidosis, dFLC is confirmed as a relevant prognostic factor, along with European Mayo stage.
Abstract
Topic: Prognosis AL
Background: Newly diagnosed light chain amyloidosis (NDAL) is a rare disease with poor outcomes, particularly when the heart is involved. An improvement in prognosis has been achieved with the availability of more effective therapies and clinical trials (CTs). However, their strict recruitment criteria might limit the patients’ enrollment, jeopardizing the generalization of their results to real-world practice.
Objective: To evaluate the proportion of patients with NDAL excluded from CTs at our institution, analyse the exclusion causes and their outcomes compared to those patients included in CTs.
Results: We analysed 161 patients with NDAL at our institution. Thirty-nine patients (24.2%) were included in CTs, while 122 were not eligible. Causes for CT exclusion were: ASCT eligibility (19.6%), severe cardiomyopathy (16.3%), renal dysfunction (13.1%), multiple myeloma (11.4%), non-measurable disease (9%) and others (30.6%). 59% of patients in the CT group and 51.6% in the non-CT group received CyBorD or CyBorD-daratumumab. Thirty-three patients received an ASCT (4 of them in the CT group). Hematologic CR/VGPR rates were 48.7% (CT group) and 40.1% (non-CT group). One-year mortality was 25% in both groups. No differences in EFS and OS between both groups were observed, even after excluding transplanted patients.
Conclusion: In our experience, the main reason for CT exclusion was potential eligibility for ASCT. Unlike our previous observation in multiple myeloma, NDAL patients in the non-CT group didn’t have poorer outcomes. This result might be explained by the greater proportion of ASCT in the non-CT group and effective first-line therapies in both groups of patients.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Cardiac amyloidosis presents a complex clinical landscape marked by the deposition of amyloid fibrils within cardiac tissues, leading to progressive cardiac dysfunction. While scintigraphic imaging techniques, such as technetium-99m pyrophosphate (Tc-99m PYP) or technetium-labeled bone tracers, offer valuable insights into amyloid burden, their correlation with clinical symptoms remains enigmatic. We report a case of an elderly man with wild-type Transthyretin amyloidosis and the impact of patisiran.
Clinical case: An 86-year-old man presented with palpitations and dyspnea, diagnosed with unstable atrial flutter, and treated with electrical cardioversion. Tests ruled out AL amyloidosis but confirmed TTR amyloidosis via myocardial pyrophosphate (PYP) scintigraphy. Genetic testing for transthyretin gene mutations was negative. Elevated cardiac biomarkers and echocardiographic abnormalities were noted. Over 2 years of patisiran treatment, heart failure symptoms stabilized, but echocardiographic parameters and biomarkers remained unchanged. Interestingly, cardiac PYP uptake decreased progressively on scintigraphy with patisiran exposure, indicating potential treatment effects on amyloid burden: after 12 months heart/contralateral lung PYP ratio decreased from 1.62 to 1.44, which further declined after 24 months – heart/contralateral lung ratio decreased from 1.44 to 1.25 (figure).
Conclusion: In this case, a patient with wild-type transthyretin cardiac amyloidosis treated with patisiran demonstrated a reduction in myocardial uptake of PYP over a 2-year treatment period. While these findings correlated with clinical and echocardiographic stabilization, no improvement was noted in biomarkers. These observations may shed light on the intricate interplay between amyloid burden and symptomatic manifestation, emphasizing the need for tailored diagnostic and therapeutic strategies in managing this condition.
Abstract
Topic: Prognosis/Natural History Other More Rare Amyloidoses
Amyloidosis, a complex group of disorders driven by protein misfolding and subsequent amyloid fibril deposition, poses a significant threat to global health. Amyloidosis associated with chronic inflammation, for instance, Amyloid A (AA) amyloidosis in the context of Mycobacterium tuberculosis (M.tb) infection, remains to be fully elucidated. To decipher the natural history of TB-associated amyloid formation, we present an investigation for organ-specific amyloid deposition in response to M.tb infection in Swiss albino mice as a non-genetic model. Infection was established through aerosolization to replicate the transmission mode in humans and was confirmed using a colony-forming unit assay. Congo red staining of four-week infected mice revealed apple-green birefringence under polarized light, signifying amyloid deposition in the intestine, heart, and lungs, suggesting a systemic deposition. However, no amyloid deposits were observed in tissues from control, non-infected animals. The results were further validated using thioflavin-T fluorescence.
Immunohistochemical analyses targeting serum amyloid A (SAA) protein confirmed these amyloids to be AA-type. A significant increase in SAA concentration was also observed in infected animals compared to controls. This study, therefore, reveals a rapid and AA-specific amyloid deposition concurrent with TB infection within a concise four-week time frame. For comprehensively characterizing the biochemical nature of the amyloid deposits, high-throughput techniques of amyloid typing, including laser capture microdissection combined with mass spectrometry, will be further employed. The observed findings not only advance our understanding of amyloidosis in TB but also advocate the utilization of this non-genetic model as a valuable tool in accelerating research in this domain.
Abstract
Topic: Imaging
Subtopic: Cardiac
Data regarding evolution over time of conduction and rhythm disorders in transthyretin wild-type transthyretin cardiac amyloidosis (ATTRwt) is scarce.
The baseline and follow-up ECG traces and Holter monitoring of patients treated with tafamidis from our prospectively maintained database (NCT05444920) were reviewed. Changes between baseline and follow-up evaluations were tested for significance. We included 265 patients (). Follow-up evaluations were scheduled at 12 months. At baseline, 54 (21%) patients had history or permanent (70[28%]) atrial fibrillation (AF). Forty-one (16%) had a cardiac implantable electronic device, plus 17 (6%) undergoing implantation during follow-up. Median PR interval was 200 (180–230) msec, with a trend toward prolongation at follow-up (p = .055). QRS duration increased over time (100[90–122]vs120[90–140]msec, p = .002) with longer QRS duration in 57% of patients at follow-up, together with prevalence of conduction disturbances (left anterior fascicular block, 52[23%]vs46[30%], p = .008; right bundle branch block 31[14%]vs29[19%], p < .001), with 16% and 12% of patients respectively, developing these abnormalities during follow-up. AF was common on Holter (29[25%]vs26[45%], p = .039), with 21% of patients having the arrhythmia detected at follow-up. Ventricular ectopic beats were highly prevalent (∼90%), although a burden >10% was found only in 2 patients at follow-up. Non-sustained ventricular tachycardia was found in 34%vs31% (p = .804). Atrio-ventricular blocks were detected in 15%vs20% (p = .754), and pauses >3 seconds from 4% up to 7% of patients at follow-up. Conduction and rhythm disorders are common in ATTRwt, with progression and worsening over time. Ageing and cardiovascular comorbidities might influence these findings. Larger prospective case-control studies will clarify the potential impact of tafamidis in modifying patients’ arrhythmic profiles.
Table 1. Baseline clinical and instrumental features of the study population.
Abstract
Topic: Diagnosis ATTRv
Background: Genetic testing may be useful in individuals with suspected cardiac amyloidosis. This study aims to establish the diagnostic yield of early gene panel testing.
Method: All consecutive patients with suspected cardiac amyloidosis without a known familial genetic variant for amyloidosis referred to the University Medical Center Groningen, the Netherlands, between 2017 and 2023 were enrolled. Patients underwent genetic testing using a gene panel, irrespective of their Perugini grade cardiac tracer uptake.
Results: 219 unrelated patients underwent genetic testing. Eleven (5%) had a pathogenic variant. Seven had hereditary transthyretin amyloidosis (ATTRv), four had a pathogenic variant in another gene (APOC2, GSN, APOA1, OSMR). Mass spectrometry typing of amyloid showed ATTR amyloid in the APOC2 carrier. There were no extracardiac symptoms associated with the mutated GSN gene. Therefore, these two patients were diagnosed with wildtype ATTR (ATTRwt). All these ATTRv and ATTRwt patients had Perugini grade 2–3. One patient with a pathogenic APOA1 variant, consistent with mass spectrometry typing, had Perugini grade 1. One patient had a pathogenic OSMR variant and Perugini grade 0 without disease manifestations associated with the mutated OSMR gene (Figure 1).
Conclusion: The yield of genetic testing in patients with suspected cardiac amyloidosis was 5%. Genetic testing may be helpful in cases with suspected amyloidosis and Perugini grade 0–1. Although gene panel testing revealed two rare non-TTR pathogenic variants (APOC2, GSN) among patients with Perugini grade 2–3, these patients were diagnosed with ATTRwt, suggesting that genetic testing of TTR is sufficient for patients with Perugini grade 2–3 in our population.
Copyright for this individual abstract is: © 2024 University Medical Center Groningen. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Basic Science Other More Rare Amyloidoses
Introduction: Localized amyloidosis refers to the deposition of amyloid fibrils in specific organs. Airways, bladder, eyes, and digestive tract are the most common sites. When amyloid deposits are found on biopsy, it is imperative to look for involvement in other sites. We describe 3 cases of amyloidosis that were initially seen as localized and, after further investigation, two of them were systemic.
Methods: Observational case series study
Casuistry: Three patients, all male, presented with localized amyloid fibril deposition. Clinical characteristics are listed in Table 1. P1: had episodes of hoarseness associated with chest pain, fever, and diarrhea. A laryngeal biopsy showed amyloid deposits in the trachea. P2 and P3 had tumor lesions on the ocular conjunctiva. Mass spectrometry: P1 and P3 had lambda-type light chain amyloid deposit and P2 macular amyloid deposit. Cardiac magnetic resonance results: P1: significant hypokinesia and late enhancement in the inferolateral wall; P2: symmetrical left ventricular hypertrophy (probably related to aortic stenosis); P3: septal thickness of 13 mm and a slight increase in the T1 map (1162).
Comments: Only in P2, who had macular amyloidosis, a protein located exclusively in the skin, it was easy to exclude systemic involvement. In P1 systemic involvement was considered, and the patient received specific therapy for light chain amyloidosis. In P3, the cardiac resonance findings were not sufficient for the hematologist to recommend treatment.
Conclusions: Despite laborious diagnostic workout, it is a challenge to differentiate between localized and systemic amyloidosis.
Abstract
Topic: Diagnosis ATTRv
Introduction: Amyloidosis are protein-misfolding disorders associated with deposition of amyloid proteins in multiple organs and progressive organ dysfunction. Familial transthyretin amyloidosis (ATTRm) usually presents itself as a progressive polyneuropathy, but also as cardiomyopathy, nephropathy, and vitreous opacities. Single features rarely remain isolated. We describe a patient with ATTRm who had sustained ventricular tachycardia as an isolated symptom.
Case Report: A 61-year-old Brazilian man, with medical history of hypertension, Portuguese parents, complaining of chest pain followed by palpitations 1 h before admission to the emergency room. Intense sweating and high heart rate (196 beats/min) were observed. ECG revealed sustained ventricular tachycardia. He was successfully submitted to electrical cardioversion and a cardioverter defibrillator was implanted. Biological markers for myocardial necrosis were high but a coronary angiogram revealed no significant contribution. Echocardiogram showed ejection fraction of 66%, diffuse hypertrophy (septum 19 mm and posterior wall 15 mm), moderate atrial enlargement and relative apical sparing pattern. Cardiac magnetic resonance showed diffuse late gadolinium enhancement of non-ischemic pattern, circumferential, and myocardial edema, suggesting amyloidotic cardiomyopathy. Molecular analysis of TTR gene evidenced a p.Val50Met mutation.
Conclusion: TTRm as cause of Sustained Ventricular Tachycardia should be considered. Val50Met is a pathogenic mutation characterized, mainly, by being clinically expressed by polyneuropathy (PAF). When cardiomyopathy is present, usually heart failure is the main clinical expression. In this case, ventricular arrhythmia was the only feature. This case highlights the risk of sudden cardiac death in ATTRm.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: A ‘dirty’ 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) whole body scintigraphy (WBS) with diffuse soft tissue uptake, extensively attenuated bone uptake, and an apparent photopenic liver is uncommon, but not exceptional.
Aim: Demonstrate the scintigraphic features of this clinical entity in patients with endomyocardial biopsy proven transthyretin cardiomyopathy (ATTRcm)
Method: Patients with biopsy proven ATTRcm were reassessed for a ‘dirty’ appearance of the WBS, commonly accepted as representing diffuse soft tissue uptake.
Results: Five patients, all males, aged 65–88, were included, 4 with Perugini grade 3 and 1 Perugini grade 1.
The incidence was close to 10 % of patients with biopsy proven ATTRcm. Three patients were alive at the study end, median follow up 2 years. The Perugini grade 1 had biopsy proven cutaneous short chain amyloidosis (AL), and combined AL and ATTRcm, endomyocardial biopsy showing 28% ATTR and 8% AL, and septal thickness of 20 mm. The four Perugini grade 3 had characteristic ATTRcm (Fig 1).
Discussion: Diffuse soft tissue uptake and extensively attenuated bone uptake, giving a ‘dirty’ WBS, is probably related to diffuse amyloidosis. The liver has normally only slight uptake on a DPD WBS, but an apparent photopenic liver is particularly evident in these patients.
Conclusion: On WBS with high background activity, the apparent photopenic liver is attributable, at least in part, to the contrast created by the surrounding high soft tissue uptake in lungs, adipose tissue, gut, and muscles.
Abstract
Topic: Pathology
Background: New immunoglobulin free light chain (FLC) assays have reached the market in the past years. Despite analytical differences, use free light chain ratios (FLCr) generated by different assays and apply similar cut-points for diagnosis of multiple myeloma seems possible. However, using different assays for risk stratification in monoclonal gammopathy of undetermined significance (MGUS) patients remains unknown.
Methods: Patients diagnosed with MGUS (n = 923) had FLC testing done using a nephelometric FreeLite (Binding Site) on BNII instruments (Siemens) and Sebia FLC assays (Sebia) on a DS2 ELISA analyzer (Dynex). Patients were followed-up for progression to any plasma cell dyscrasia (PCD) for several decades. The Mayo MGUS risk stratification model for progression was assessed with both assays (M-spike >1.5 g/dL; non-IgG isotype and abnormal FLCr), using package insert reference intervals (RI) and a new metric called principal component 2 (PC2).
Results: There were 94 events of progression to PCD in the cohort during a median of 38 years of follow-up (range 0–47 years). Freelite and Sebia FLC showed similar hazard ratios in the risk models when elevated FLCr were present. When low FLCr was present, Sebia’s RI was not significant. An alternative clinical decision point lower than the RI was evaluated as a risk factor, which improved patients’ stratification. The PC2 metric showed similar performance to the FLCr in models, without superior benefit.
Conclusions: We have demonstrated that a new ELISA based FLC assay can be employed in MGUS risk stratification models with similar performance to the reference assay.
Abstract
Topic: Basic Science ATTR
The mechanism that converts native human transthyretin into amyloid fibrils in vivo is still unclear and debated. The fibrillogenesis of globular proteins in in vitro models is commonly achieved using non-physiological conditions of pH, temperature, or organic solvents. Transthyretin amyloid formation can instead be achieved under physiological conditions through a mechano-enzymatic mechanism involving specific serine proteases such as trypsin or plasmin. We studied S52P and L111M transthyretin variants, both causing a severe form of systemic amyloidosis mostly targeting the heart at a relatively young age with heterogeneous phenotype among patients. Our investigation of thermodynamics shows that both proteins are significantly destabilized when compared to other amyloidogenic variants. However, despite showing a similar thermodynamic stability, the L111M variant seems to have enhanced susceptibility to cleavage and a lower tendency to form fibrils than S52P in the presence of specific proteases and biomechanical forces. Heparin strongly enhances the aggregation propensity of L111M transthyretin but has no to minimal effect on the S52P variant. Similarly, fibrillar seeds affect the fibrillogenesis of both proteins, with a stronger effect on the L111M variant. According to our model of mechanoenzymatic fibrillogenesis, both full-length and truncated monomers, released after the first cleavage, can enter into fibrillogenesis or degradation pathways. Our findings show that the kinetics of the two processes can be affected by several factors, such as intrinsic amyloidogenicity due to the specific mutations, environmental factors including heparin and fibrillar seeds that significantly accelerate the fibrillogenic pathway.
Abstract
Topic: Treatments of AL
Aim: Light chain amyloidosis (AL) is an incurable clonal plasma cell disorder characterized by the deposition of immunoglobulin light chain in tissues, resulting in organ dysfunction. This retrospective, single-center study aims to determine the hematologic response in patients receiving first-line Daratumumab therapy in two different combinations: D-VCD and DRD. DRD protocol was preferred for patients with severe neurological involvement and for those diagnosed before January 2023 when D-VCD was reimbursed in Romania.
Methods: Between January 2021 and December 2023, 53 patients were diagnosed with AL Amyloidosis at the Fundeni Clinical Institute, Romania with 38 patients received Daratumumab therapy. Two subgroups were formed: one following D-VCD protocol (n = 23) and DRD protocol (n = 15).
Results: The median age at diagnosis was 61.5 years (range, 44–77); 25 patients (65%) had ≥3 organ involvement, with cardiac involvement in 21 pts (55%). All patients with severe neurological involvement (n = 5, 33.3%) received the DRD regimen (). At 2 months, 88.2% of patients undergoing D-VCD treatment achieved ≥ VGPR, while the DRD group reached ≥ VGPR in 33.3% of patients (p = .010, Chi2). For patients receiving DRD, 55.5% and 75% achieved ≥ VGPR at 6 and respectively 12 months. 6 patients (15.7%) underwent ASCT, all of whom following D-VCD protocol and currently maintaining ≥ VGPR. Median survival for both groups has not been reached without significant group differences.
Table 1. General characteristics of patients treated with DRd and D-VCd, respectively.
Conclusions: Despite D-VCD leading a quicker hematologic response, DRd as initial treatment for AL patients achieves deep hematologic responses at 6 and 12 months and may be a practical choice for those with severe neurological involvement.
Abstract
Topic: Diagnosis AL
AL Amyloidosis is an uncommon plasma cell disorder that presents with non-specific symptoms which often lead to either misdiagnosis or delayed diagnosis. The outcome of AL Amyloidosis depends on age, early detection, treatment and the extent of organ or system involvement.
Aim of the study: To study the diagnostic challenges in AL Amyloidosis, their effect on organ involvement and prognosis of patients in a single centre.
Materials and Methods: A total of 16 patients diagnosed with AL Amyloidosis between June 2019 and June 2023 were evaluated for the delay in diagnosis, organ involvement, prognosis, and outcomes.
Results: Out of 16 patients, 12 were males and 4 were females. The median age of presentation was 53 years (42–71 years). Most patients initially presented to nephrologist followed by general practitioner then cardiologist. The median time taken for diagnosis was 9.3 months from the first symptom onset. The most common presenting symptoms were pedal edema, shortness of breath and generalized weakness in 62.5% (10 patients). More than two organ involvement is seen in 50% (8) of patients and the most common organs involved were kidney and heart. Most of our patients received CyborD regimen (14), 2 patients received Dara-CyborD followed by an Autologous stem cell transplant. Mortality was observed in 37.5% (6) with the most common cause of death being cardiac related.
Conclusion: In AL amyloidosis vague presentation with non-specific symptoms is associated with misdiagnosis or delayed diagnosis. Delayed diagnosis and involvement of more than 2 organs especially severe cardiac involvement were associated with poor prognosis.
Abstract
Topic: Treatments of AL
We showed that autologous stem cell transplant (ASCT) can be deferred in patients with AL amyloidosis who achieve satisfactory response (i.e. partial response or very good partial response with organ response, or complete response) after cyclophosphamide/bortezomib/dexamethasone (CyBorD). We expanded enrollment and extended follow-up. Patients diagnosed between 2009 and 2021 eligible for ASCT according to ISA guidelines received CyBorD and did not proceed to transplant in case of satisfactory response. One-hundred ninety-five patients were included. Eighty-two (42%) achieved a satisfactory response after CyBorD. Of 113 patients with unsatisfactory response, 77 (68%) underwent ASCT and 41 (32%) received rescue therapy (daratumumab in 19 [46%], IMiDS in 14 [37%] and MDex in 7 [17%]) due to loss of eligibility/refusal. Response rates are reported in Figure 1A. After a median follow-up of 6.3 years, 62 patients (32%) died (1 within 100 days). There was no difference in survival (80% vs. 84% at 5 years, p = .538) and median time to next treatment or death (median 60 vs. 62 months; p = .803) between patients who received CyBorD alone or followed by ASCT. Standard IMiDs or MDex rescue was associated with poorer survival (42% at 5 years, p < .001); whereas daratumumab-based rescue granted similar survival to that observed in responders to CyBorD/ASCT or CyBorD alone (63% at 5 years, p = .287; Figure 1B). This sequential, response-driven approach to treat ASCT-eligible patients is safe and effective. Daratumumab-based rescue seems to overcome the poor outcome of non-responders. The introduction of daratumumab in induction further reduces the need to proceed to ASCT.
Abstract
Topic: Diagnosis AL
IgM-associated light chain amyloidosis (AL) is an uncommon cause of systemic AL and a diagnosis of concurrent Waldenstrom’s Macroglobulinemia (WM) with AL is rare. We describe a 78-year-old male who was admitted with progressive mediastinal lymphadenopathy and left-sided pleural effusion. He initially underwent a mediastinoscopy with lymph node biopsy. Pathology was consistent with amyloidosis as confirmed on Congo-red staining. Further analysis with liquid chromatography in tandem with mass spectrometry for amyloid typing showed AL (lambda) subtype. Evaluation of his normocytic anemia with paraproteinemia studies showed two monoclonal bands (IgM kappa and IgA lambda) (). Initial flow cytometry of the lymph node, pleural fluid, bone marrow aspirate, and biopsy analysis were negative for clonal B-cell disease, but marrow cytogenetics were positive for MYD88 (p.L265P). The patient continued to deteriorate clinically with progressive hypoxia and neutropenia. Reassessment of flowcytometry of pleural fluid was non-diagnostic. A repeat bone marrow biopsy showed lymphoplasmacytic infiltrates (plasma cells ∼5–10% with slight lambda predominance) with cytogenetics and FISH showing: MYD88 + TET2 mutations and CCND1-IGH [translocation t(11;14)] gene rearrangement respectively, thus confirming the diagnosis of lymphoplasmatic lymphoma(LPL) (). Given concern for autoimmune neutropenia high dose steroids were administered and WM directed therapy using bendamustine and rituximab was initiated. There is a paucity of data in literature to guide appropriate treatment of IgM-associated AL. Consideration of incorporating AL directed therapy with standard LPL treatment is warranted. This case also illustrates the predominance of pulmonary and nodal involvement in IgM-associated AL with LPL.
Table 1. Significant laboratory and imaging findings at the time of diagnosis of lymphoplasmacytic lymphoma.
Abstract
Topic: Prognosis ATTR
ATTRv amyloidosis due to p.Glu109Gln mutation is characterised by onset in the 5th–6th decade, prevalent distal paraesthesias/CTS as presenting symptoms and early heart dysfunction. Heart failure and sudden death are the major cause of mortality followed by dysautonomia and cachexia. Prior to the availability of patisiran and inotersen we reported a life expectancy of 7.6 ± 3.7 (3–13) years in a cohort of 40 patients. The objective of this single-center real world study is the description of cardiac function in a cohort of patients with p.Glu109Gln mutation in whom patisiran therapy for polyneuropathy was started.
At time 0, six out of ten patients presented parameters consistent with a picture of cardiac hypertrophy with maintained ejection fraction with a mixed phenotype and elevated troponin T and NT pro BNP values. Four out of ten patients presented normal cardiac function parameters with only a neuropathic phenotype and normal NTproBNP and Troponin T values.
During follow-up of 27.8 months (6–54), 8 patients showed stability of echocardiographic and serological parameters with absence of cardiac symptoms. One patient had a reduction in troponin values despite ultrasound parameters, NT-pro BNP remain substantially unchanged, and another one experienced a reduction of the ejection fraction with the appearance of heart failure symptoms.
In this study, the use of patisiran allowed substantial stability of the cardiological picture in the majority of patients with amyloidosis associated with the p.Glu109Gln variant. A greater number of patients and prolonged follow-up will be necessary for greater robustness of these findings.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Quantitative technetium-99m-pyrophosphate cardiac SPECT/CT (99mTc-PYP SPECT/CT) is an emerging non-invasive method for estimating myocardial transthyretin cardiac amyloidosis (ATTR-CA) at diagnosis, but its efficacy in monitoring changes with transthyretin stabilization therapy remains unclear.
Objective: To investigate longitudinal changes in quantitative 99mTc-pyrophosphate (PYP) SPECT/CT following TTR stabilization therapy.
Methods: 18 participants (median age 80 years, 94% male) with ATTR-CA (16 wild-typeATTR-CA and 2 hereditaryATTR-CA) underwent baseline and follow-up (median 2.9 years) 99mTc-PYP SPECT/CT using a general-purpose-cadmium-zinc-telluride-scanner. All received transthyretin stabilization therapy (17 tafamidis and 1 diflunisal, median duration 2.6 years) and two were concurrently enrolled in a transthyretin silencer clinical trial. We calculated left ventricular (LV) standardized uptake values (SUV) (SUVmax, SUVmean), cardiac amyloid activity (CAA; SUVmean*LV activity volume), and percent injected dose (%ID) (mean activity concentration*LV activity volume/injected activity), using a threshold of 1.5 times left atrial blood pool on SPECT/CT images. Longitudinal changes were analyzed using Wilcoxon signed-rank test.
Results: Following therapy, multiple quantitative Tc-99m-PYP metrics decreased significantly: SUVmax: median −0.91 (IQR: −1.02, −0.05, p = .003), CAA: median −420.6 (IQR: −700.72, −242.48, p < .001), and %ID: median −0.49 (IQR: −0.76, −0.27, p < .001) (Figure 1). There was a minimal, but statistically significant worsening of global longitudinal strain (GLS) on echocardiogram (median change 0.9%, p = .049). LV mass, LV wall thickness, NTproBNP, troponin, and estimated glomerular filtration rate remained stable.
Conclusion: Transthyretin stabilization therapy significantly reduced multiple quantitative 99mTc-PYP SPECT/CT metrics. Given lack of improvement of LV strain and other noninvasive parameters, further investigation is needed to understand the implication of these changes.
Abstract
Topic: Prognosis AL
Current staging and response criteria in AL amyloidosis stemmed from retrospective studies limited by sample size, patient selection, and lack of molecular data. Moreover, validated hematologic progression criteria are still lacking.
In the frame of the EUREKA Consortium (NCT06205953), funded by the European Joint Program for Rare Diseases, we have started to create a large prospective registry collecting all new, consecutive cases of AL amyloidosis evaluated at 4 referral Centers across Europe (Pavia-Italy; Heidelberg-Germany; Utrecht-The Netherlands; Pamplona-Spain) or at their satellite sites. The prospective, REDCap-based registry is linked to a cross-border biorepository and sample sharing network for molecular/phenotypic profiling of clonal plasma cells (RNA sequencing, low-pass WGS, circulating tumor cell analysis) and light chains (sequencing, N-glycosylation analysis, and phenotypic assessment in a 3D heart-on-a-chip model). A fifth site (Muttenz-Switzerland) endows big data analysis and artificial intelligence applied to health.
We aim at:
defining the impact of molecular profiling on disease phenotype to promote early diagnosis and patients’ stratification and to guide therapeutic choices;
describing real-world presentation (including subjects who are usually excluded from clinical trials), access to treatments, and outcome (including quality of life);
defining the role of standard and new tools for assessing minimal residual disease after treatment.
Besides deepening our current understanding of the biology of AL amyloidosis, the data produced within this study will be instrumental in promoting early diagnosis, personalizing individual patient management and in the design of future clinical trials. The Consortium is open to other centers worldwide wishing to contribute to this study.
Abstract
Topic: Prognosis AL
Amyloidosis represents a heterogeneous group of misfolding protein disorders characterized by amyloid fibrils deposition in various tissues and organs. Over 36 different amyloidogenic proteins have been identified, but only 9 of them are involved in cardiac amyloidosis, light chain (AL) and mutant or wild-type transthyretin (ATTR) being the most common forms.
In systemic AL amyloidosis, clonal plasma cells produce amyloidogenic light chain fragments causing organ damage including the heart and kidneys. It remains a rare and life-threatening disease, since morbidity and mortality of patients are strongly associated with the severity of cardiac involvement. Early diagnosis and identification of the amyloid protein involved are thus crucial. However, despite advances in diagnostic methods, the diagnosis of AL amyloidosis and/or cardiac amyloidosis is often delayed due to the non-specificity of presenting symptoms. Disease awareness and a high index of suspicion are key elements for early diagnosis, in order to initiate timely appropriate therapy to prevent further organ damage. We retrospectively analyzed data related to cardiac involvement from 43 consecutive patients with AL amyloidosis who were diagnosed at our institution between 2007 and 2023.
Heart involvement was present in 35 (81%) of them while 63% (n = 22) had severe cardiac disease as of stage IIIa and IIIb, according to the Mayo2004/European staging system.
Almost one third of these patients experienced an early death occurring the first 6 months of diagnosis.
To capture everyday clinical practice, we will provide details on clinical presentation, diagnostic challenges, and patient outcome.
Abstract
Topic: Diagnosis ATTRv
Hereditary transthyretin amyloidosis (hATTR) is determined by over 130 TTR gene mutations. The Ile107Val mutation (I127V) is rare, with approximately 50–60 reported cases, characterized by a mixed phenotype, late onset and neurological symptoms involving painful paresthesia, along with cardiac involvement. It is also frequently related with demyelination and carpal tunnel syndrome (CTS). Particular manifestations include tongue atrophy and fasciculations, and central nervous system involvement.
In Romania, the most common mutation is Glu54Gln (E74Q) identified in 35 patients from the North-East region, linked to a mixed phenotype, early onset, and an aggressive clinical course. Mutations like Val30Met, Glu98Lys, Glu89Val, and Ile107Val have also been reported.
Our goal is to provide a clinical description of two symptomatic Val107 hATTR patients, with a positive familial history for hATTR from unrelated families.
Both symptomatic patients had an average onset-to-diagnosis time of 4 years. TTR gene sequencing revealed a Val107 mutation, and the abdominal fat-pad biopsy confirmed the presence of amyloid deposits
The first patient (65-year-old male) had bilateral CTS, severe sensory-motor axonal polyneuropathy in the lower extremities, and minimal cardiac involvement. The second case (56-year-old male) also had CTS and neurological involvement without cardiac involvement.
Family screening in both cases confirmed the mutation in two asymptomatic family members.
The clinical manifestation in Romanian individuals with Ile107Val hATTR is less severe than in those with Glu54Gln hATTR, and it differs slightly from patients with the same mutation recorded in other studies.
Our research highlights the clinical heterogeneity of mutations found in hATTR patients in Romania.
Table 1. General characteristics of symptomatic and carriers diagnosed with hATTR Ile107Val and Glu54Gln.
Abstract
Topic: Prognosis ATTR
Generally, electromyography and nerve conduction studies are the main diagnostic and prognostic biomarkers in peripheral neuropathy clinical practice; nevertheless, they may lack responsiveness in the context of Hereditary transthyretin amyloidosis (ATTRv).
This study will primarily focus on the use of blood biomarkers of peripheral neuropathy for early diagnosis and clinical management in patients with polyneuropathy associated with different TTR variants.
We carried out a single centre, observational, prospective, longitudinal study on 28 ATTRv patients and 7 carriers in the predicted age of disease onset (PADO). The most frequent variants in our cohort were p.Phe84Leu and p.Glu109Gln. We used the SiMoA technique to measure serum content of total tau protein and neurofilament.
Blood samples were collected at time 0 after 6 month and after 1 year from both healthy control and presymptomatic TTR mutation carriers. At the same time, we have performed the familial amyloid polyneuropathy (FAP) stage, the polyneuropathy disability score (PND), CADT and neuropathy impairment score for lower limbs (NIS-LL). Renal and cardiological function were also monitored. All patients were on patisiran, inotersen or tafamidis.
Our findings strongly support the integration of serum NfLs into the diagnostic and monitoring framework for ATTRv amyloidosis. This study contributes valuable insights to the field, paving the way for improved clinical management and enhanced understanding of the disease course.
Abstract
Topic: Prognosis/Natural History Other More Rare Amyloidoses
In AA amyloidosis attaining low levels of serum amyloid A (SAA) is associated with prolonged survival. Here we propose new renal response and progression criteria for AA amyloidosis. The study was conducted in the Pavia prospectively maintained database of newly diagnosed patients with AA amyloidosis. Cut-offs of variations in 24 h-proteinuria and estimated glomerular filtration rate (eGFR) (at 12 months) from baseline best predicting end-stage renal failure (RF) at 24 months were identified by ROC analysis. Impact of SAA normalization (i.e. <6.4 mg/L; at 12 months) on RF was also evaluated. Of 233 patients 147 (63%) had a second evaluation. Kidney involvement was present in 140 (95%) cases. Nineteen (13%) patients were already on dialysis at diagnosis and were excluded. After a median follow-up of 7.2 years, 36 (24%) patients died and 53 (41%) progressed to RF. A reduction of 24 h-proteinuria >40% from baseline, without a worsening of eGFR >20% best predicted progression to RF (at 5 years: 5% vs. 26%, p = .035; Figure 1A) and was selected as candidate renal response criterion. A reduction of eGFR >20% from baseline predicted shorter time to RF (at 5 years: 13% vs. 31%, p = .002; Figure 1B). Finally, SAA normalization resulted in prolonged time to RF (at 5 years 7% vs. 36%, p < .001; Figure 1C). We identified candidates’ renal response and progression criteria which are ongoing validation in the Heidelberg cohort.
Abstract
Topic: Pathology
Background: Cardiac AL/ATTR amyloidosis is a potentially fatal cardiomyopathy. No well accepted methods for amyloid quantification exist. It is unclear how well imaging studies (Scintigraphy, MRI) correlate with histologic amyloid burden. Traditional histologic scoring systems can be biased, low throughput, semi-quantitative and difficult to generalize. This study aims to quantify amyloid burden in endomyocardial biopsies by training a computer vision model to identify endocardial, vascular, fat and interstitial deposits.
Methods: Whole slide images of SAB stains from 15 unique specimens captured on an Aperio GT 450 scanner were used for model training in Aiforia Cloud Create. Trained experts annotated 384 regions in the training images and the model was trained for 1000 iterations using high complexity, a 50 um field of view and minimal image augmentation. Other parameters were adjusted in parallel to train 8 slightly different models, in time for submission to this meeting. Validation was performed in a distinct hold-out set of seven images comprising 56 regions.
Results: Initial results in this limited validation set and considering the best performing model demonstrated a total error area error rate of 8.1%, an F1 score of 71.57% a precision of 74%, sensitivity if 69%. Main sources of error include images with different staining intensity and misclassification of amyloid location (vessels, fat etc).
Conclusions: These early results suggest that artificial intelligence based amyloid quantification in cardiac biopsies is feasible. After additional refinement, this approach will allow us to correlate histologically defined burden with outcomes, radiologic and laboratory parameters.
Abstract
Topic: Treatments of AL
Amyloidosis is characterized by deposition of amyloid fibrils in various tissues and organs, with AL and ATTR being most common forms. Synovium is an uncommon site of extramedullary involvement in AL amyloidosis with only few cases reported so far. We described a case of synovial amyloidosis as the initial presentation of a multiple myeloma-associated AL amyloidosis.
A 73-year-old male was referred for swelling, pain, and stiffness of the left knee, with a gradual increase in complains over the past 12 months. MRI showed a large tumoral mass of 64 × 40 mm, with a diffuse synovial thickening of the knee and osteolytic lesions. CT-guided biopsy identified characteristic lambda light chains amyloid deposits. PET-scan showed an increased uptake in both knees, but also hips, shoulders, and left ankle. Additional MRI confirmed a pathological synovial thickening at all sites. Investigations identified a lambda stage IA, ISS 2, standard-risk MM, as well as a bilateral carpal tunnel syndrome, cardiac and renal amyloid involvement. A VCD combination was initiated with a significant improvement in arthritis-related symptoms. VGPR was reached after 4 cycles, but cardio markers values remained unchanged. Treatment was shifted to DRd, for 12 cycles with complete hematological response and dramatic improvement of cardio markers. Four years after diagnosis, there are no sign of relapse.
Amyloid arthropathy as initial manifestation of MM is uncommon and can cause synovial thickening, subcutaneous nodules, and erosive bone lesions, responsible for joint stiffness and arthralgia, mimicking rheumatoid arthritis. Therefore, differential diagnosis of chronic polyarthralgia should include systemic AL amyloidosis.
Abstract
Topic: Treatments of ATTR
Introduction: Within recent years, specific treatments have been approved for the two most common types of systemic amyloidosis in Europe: tafamidis 61 mg for systemic transthyretin amyloidosis (ATTR) with cardiac involvement and Daratumumab-CyBorD for systemic light-chain amyloidosis (AL). An amyloidosis clinic was established within the Oldenburg university hospital of internal medicine in oncology and hematology in October 2020. However, throughout our region with around two million inhabitants, ATTR patients in particular, have struggled to receive tafamidis, due to high treatment costs. Therefore, a clinic was also initiated in the department of cardiology in September 2022.
Methods: Analysis of amyloid patients seen and treated in both clinics between October 2020 until January 2024
Results: As the first clinic was primarily initiated in oncology in 2020 only six AL patients were treated. For 2021, a total of 25 patients were seen (22 AL, one ATTR, one SAA and one localized light-chain amyloidosis (locAL) patient). In 2022, a total of 30 patients presented with 20 AL, nine ATTR and one locAL patient. For 2023, at total of 60 patients were consulted with 31 AL, 22 ATTR, 3 SAA and two locAL patients. See figure below.
Overall, there are currently 34 AL patients being consulted with patients receiving daratumumab-based (n = 14), IMID-based (n = 4) or venetoclax-based (n = 4) combinations and 23 ATTR patients either already receiving tafamidis (n = 17) or still in work-up (e.g. concomitant gammopathy requiring cardiac biopsy).
Summary: Our clinics can provide modern therapies for amyloid patients within our region
Abstract
Topic: Prognosis AL
Background: Outcomes of patients with AL progressing to end-stage renal disease requiring dialysis is not well documented.
Objective: To report characteristics and outcomes of AL patients starting dialysis after initiation of primary therapy.
Methods: We analyzed data of 295 consecutive AL patients from three European centers which started dialysis >1 month from treatment initiation.
Results: shows cohort’s characteristics. Median time from first-line therapy to dialysis was 19.8 months; 64 (22%) patients started dialysis >5 years from diagnosis. In 33 (11%) patients, dialysis was discontinued, 9 (3%) underwent renal transplantation. At dialysis initiation, 59 (20%) patients were in hemCR/VGPR, 43 (15%) in hemPR and 60 (20%) at hematologic relapse. After starting dialysis, 112 (38%) patients received further therapy, due to hematologic relapse in 47 (42%), inadequate response in 37 (33%) and organ progression only in 26 (23%), and 47 (42%) achieved hemCR/VGPR, 17 (21%) hemPR, while 42 (38%) improved their response status. Median post-dialysis survival was 38 months and has not improved in the more recent era. Heart involvement(p < .001), BM plasma cells ≥20%(p < .001), less than hemCR/VGPR at dialysis(p = .03) and dFLC ≥50 mg/L at dialysis (p = .004) were associated with inferior post-dialysis survival in univariate analysis. Achieving ≥ hemCR/VGPR in post-dialysis treatment was associated with better post-dialysis OS(p = .011). Causes of death included disease progression in 89 (52%) patients, sepsis in 19 (11%), cardiac related in 23 (13%), renal failure in 4 (2%) and other/unknown in 37 (21%).
Table 1.
Conclusions: Patients with AL amyloidosis can have long post-dialysis survival and may benefit from further therapy; however, their management must be improved given new treatment options and renal transplantation option.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: 99mTechnetium-pyrophosphate Cardiac Scintigraphy (CS) has been repurposed for the diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) when combined with blood/urine tests to exclude monoclonal protein, with high specificity and positive predictive value near 100%.
Case report: A 38 y-old afro-descendant male with an important family history of sudden death and a 10-year history of several syncopes, dysautonomia and sensitive neuropathy, presented in 2016 to the ER with unstable bradycardia in need of a pacemaker. Four years later he presented ventricular arrhythmias in-need of an ICD implantation. Echocardiogram ventricular function was preserved, with diffuse myocardial hypertrophy (21 mm diameter); MRI demonstrated a ring-like pattern with multifocal myocardial delayed enhancement and 82 g fibrosis (37% of the ventricular mass). In 2023 Echocardiogram showed diffuse hypokinesis and lower ventricular ejection fraction =45% with hyper-refringent myocardium and restrictive hemodynamics. Although there were several clinical red flags for amyloidosis and the 2023 CS were positive (grade 3) and highly suggestive of ATTR-CM, genetic testing determined a variant on FLNC gene that combined with the epidemiology and hypertrophic phenotype actually presented us a False Positive of the CS.
Decision-making: False-positive tests in CS have been described secondary to hydroxychloroquine. Recently, it has also been shown in publications with hypertrophic cardiomyopathy spectrum of patients.
Conclusion: As CS scans are increasingly applied to broader populations of thick heart cardiomyopathies, this case-report highlights the potential for false-positive results.
Abstract
Topic: Diagnosis AL
Background: AL amyloidosis is caused by deposition of misfolded immunoglobulin light chains. There can be a rapid progression to ESKD. In this case report, we described a 63-year-old woman with de novo AL amyloidosis in renal allograft occurring after 4 years following kidney transplantation.
Case: A 63-year-old woman with a history of hypothyroidism, diabetes mellitus and nephrolithiasis underwent living donor kidney transplantation from her sister for ESKD in 2015. She presented with proteinuria in 2019. Laboratory investigations revealed creatinine 2.53 mg/dL, albumin 2.85 g/dL and urinary protein 8.8 g/day. Renal allograft biopsy disclosed AL amyloidosis. IgG/lambda monoclonal protein was found. Serum free lambda light chain was 256 mg/L with a kappa/lambda ratio of 0.21. The bone marrow biopsy showed 10% lambda restricted plasma cells. The patient had stage IV (revised Mayo 2012) disease with heart, kidney, and autonomic nervous system involvement. The native kidney tissue disclosed no evidence of amyloidosis. CyBorD was started and maintenance immunosuppression was continued. After 6 cycles, VGPR with organ response was achieved and maintained for 14 months. The patient died of COVID-19 pneumonia in 2021.
Summary and conclusion: Recurrence of AL amyloidosis in a renal allograft after transplantation is not an uncommon scenario but de novo AL amyloidosis in kidney graft is extremely rare. The few cases reported, and the patient described here are summarized in the table. AL amyloidosis should be included in the differential diagnosis of new onset albuminuria in a patient with kidney transplantation. Concomitant immunosuppressive therapy challenges treatment of these patients.
Table: Reported cases of de novo AL amyloidosis in kidney allograft
References
- Le QC, Wood TC, Alpers CE. De novo AL amyloid in a renal allograft. Am J Nephrol. 1998;18(1):67–70. doi: 10.1159/000013308.
- Chen DJ, Jiang H, Yang H, He Q, Wang HP, Chen JH. Unusual cause of proteinuria and re-renal failure after kidney transplantation: de novo localized AL amyloidosis in renal allograft. Int Urol Nephrol. 2010;42(2):507–511. doi: 10.1007/s11255-009-9635-9.
- Qian Q, Nasr SH, Fidler ME, Cornell LD, Sethi S. De novo AL amyloidosis in the kidney allograft. Am J Transplant. 2011 Mar;11(3):606–12. doi: 10.1111/j.1600-6143.2010.03418.x. Epub 2011 Feb 7. PMID: 21342449.
- Fotiou D, Skalioti C, Liapis G, Marinaki S, Kastritis E. De Novo AL Amyloidosis in Renal Allograft and Anti-CD38 Monoclonal Antibody Treatment. Hemasphere. 2021;5(12):e665. Published 2021 Nov 17. doi: 10.1097/HS9.0000000000000665.
Abstract
Topic: Prognosis ATTR
Introduction: CA is associated with various complications, and one of them are TEEs, which can significantly impact patients’ quality of life. Predicting and managing the risk of these TEEs in patients without atrial fibrillation (AF) pose significant challenges, as many occur independently of AF presence. Several predictors, particularly echocardiographic ones, have been linked to an increased risk, but there is no consensus on stratification or preventive treatment.
Objectives: To determine the prevalence of TEEs in a cohort of CA patients without AF and identify echocardiographic predictors.
Methods: A retrospective, single-center study including confirmed CA patients. A pre-specified list of variables was defined, and only patients with at least 70% of these variables were included. Risk rates were analyzed through binary logistic regression, with a significance level set at p <0.05.
Results: 75 patients were included. Baseline characteristics are depicted in Figure 1. Fifteen TEEs (20%) were described, with 80% being ischemic strokes. While diastolic dysfunction and pulmonary systolic arterial pressure (PSAP) were predictors in univariate analysis, the multivariate backward LR model identified interventricular septum diameter (IVSD) as the sole predictor, OR 1.280 (1.061–1.543), p = .010. ROC curve analysis revealed that IVSD had good predictive power for TEEs (AUC 0.745), with a cutoff of ≥15 mm providing 80% sensitivity and 62% specificity (see Figure 1).
Conclusions: An IVSD ≥15 mm, as assessed by echocardiography, demonstrated robust predictive capability for TEE risk in this cohort of CA patients without AF.
Abstract
Topic: Imaging
Subtopic: Echo
Data regarding evolution over time of echocardiographic features in TTRwt amyloidosis is scarce. The baseline and follow-up echocardiograms of patients treated with tafamidis from our prospectively maintained database (NCT05444920) were reviewed. Changes between baseline and second follow-up evaluations (scheduled at 12 months) were tested for significance.
We included 151 patients (). There were no significant differences between baseline and follow-up in terms of left ventricular (LV) geometry (median interventricular septum thickness 18 [15–20]vs18 [16–20]mm, p = .377; end-diastolic diameter 45 [40–49] vs 43 [40–49] mm, p = .890) and systolic function (ejection fraction 50 ± 11% vs 49 ± 11%, p = .054; global longitudinal strain −12.3 ± −3.6% vs -12.4 ± −5.1%, p = .788). Similarly, we did not find significant differences in terms of LV filling pressures (increased in 91 vs 85% of patients, p = .219; E/e’ ratio 16.8 [11.2–20] vs 14.5 [12.6–19.2], p = .071) and left atrial (LA) size (mean LA volume indexed for body surface area 46 ± 16 v s48 ± 12 mL/m2, p = .410). Moreover, right ventricular longitudinal function assessed through the tricuspid annular plane systolic excursion (TAPSE) was similar between baseline and follow-up (17 [14–20] vs 17 [14–20] mm). Finally, there were no significant changes of estimated pulmonary artery systolic pressure – ePASP (40 [33–45] vs 35 [30–44] mmHg) over the follow-up period. Tafamidis may prevent worsening of the main echocardiographic indices used to monitor cardiac remodeling and dysfunction induced by amyloid infiltration. Larger case-control studies with longer follow-up will clarify the potential impact of tafamidis in improving these echocardiographic indices, and their utility (with best cut-off values) to predict and monitor treatment response.
Table 1. Baseline clinical and instrumental features of the study population.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: Molecular imaging using PET/CT in ATTR-CA provides detailed information on the extent and quantity of systemic amyloid load, which could be valuable to track serially in the context of emerging therapies.
Objective: To quantify cardial amyloid burden on 124I-evuzamitide PET/CT, and correlate it with disease measures including NYHA class, Columbia stage, cardiac biomarkers, quality of life and functional parameters.
Methods: Myocardial uptake was measured volumetrically on static images with PMOD (Bruker, Switzerland), using automatic iso-contouring with a threshold of mean left atrial (LA) volume of interest (VOI) activity +2 standard deviations of blood pool activity concentration. The primary left ventricle (LV) uptake metric was percent injected dose (%ID), calculated as VOI mean activity concentration x VOI volume/injected activity. Additionally, cardiac amyloid activity (CAA) was analyzed as VOI SUVmean x VOI volume. Correlations were quantified using Pearson’s r with 95% confidence intervals.
Results: 25 subjects were scanned; 18 had myocardial uptake on 124I-evuzamitide PET/CT (11 with ATTRv-CA and 7 with ATTRwt). There was a strong correlation between cardiac amyloid load, defined by both %ID and CAA, and high sensitivity troponin T (hs-TnT) and Columbia score. There was a moderate correlation between cardiac amyloid load and NT-proBNP level, NYHA class, KCCQ summary score, and SF36 health score.
Conclusion: Quantitation of amyloid load with I124I-evuzamitide on PET/CT correlates with direct and indirect measures of the severity of ATTR-CA, quality of life, and functional status. There was a strong correlation between cardiac amyloid load, and both Columbia score and hs-TnT.
Table 1 Correlation between 124I-Evuzamitide uptake and direct and indirect markers of amyloid burden, quality of life, and functional status.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Introduction: The ATTR-QOL is a disease-specific, patient-reported outcome measure developed to capture the symptoms and impacts from patients across all types of ATTR amyloidosis (i.e. hereditary and wild-type). An observational study was conducted to confirm the domain structure, identify redundant items, develop a scoring algorithm, and evaluate the psychometric properties of the ATTR-QOL.
Methods: Adult patients with ATTR amyloidosis in the United States who were symptomatic completed the ATTR-QOL at 2 timepoints, along with additional surveys which served as criterion measures. Factor analyses and tests of differential item functioning (DIF) were conducted to confirm a hypothesized domain structure and identify redundant items. A scoring algorithm was proposed and tested. Psychometric analyses included tests of internal consistency reliability, test-retest reliability, and convergent validity.
Results: The analytic sample included 233 participants. Factor analysis and tests of DIF identified redundant items and supported the formation of 4 impact domains: Daily Activities, Social/Role Functioning, Emotional Wellbeing, and Physical Functioning. Results were confirmed with a secondary dataset. The proposed scoring algorithm was refined. Results supported the internal consistency reliability, test-retest reliability, and convergent validity of the ATTR-QOL impact domains.
Conclusions: Findings support the use of the 4 ATTR-QOL impact domains in patients with ATTR amyloidosis. This study resulted in updates to the ATTR-QOL for item reduction and the development of a scoring algorithm. Future work will be conducted in a clinical setting to explore responsiveness and establish meaningful within-patient change thresholds.
Copyright for this individual abstract is: © 2024 Amyloidosis Research Consortium.. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Imaging
Subtopic: Cardiac
Aims: We aimed to investigate which parameters of left atrial (LA) structure and function could predict new-onset atrial arrhythmias (NOAA) in patients with CA, aiding in improved follow-up.
Methods and results: We prospectively included patients diagnosed with CA, both light chain (AL) and variant transthyretin (ATTRv) with no history of AA. LA mechanical dispersion (LAMD) was defined as the standard deviation of time-to-peak positive strain and reported as percentage from the R-R interval. The primary outcome was NOAA. 93 patients were included (mean age 54.3 ± 9.8, 58% males), and 44 patients (47%) developed NOAA during a median follow up of 11 (3.5–36.0) months. Patients with NOAA had heavier hearts, worse global LV function, more LV longitudinal impairment, larger atria and worse LA function. LA reservoir strain (LASr) was significantly lower and LAMD significantly higher in patients who developed NOAA. In the multivariate analysis adjusting for confounding factors, a lower LAMD was independently associated with higher risk for NOAA (HR: 1.182, 95% CI: 1.033–1.351, p = .015). Patients with LAMD> 6.6% had a higher risk for NOAA than those with LAMD≤ 6.6% (p < .001). Furthermore, LAMD> 6.6% remained an independent predictor for NOAA in both univariate and multivariate analysis. Five models were created, and the model based on LA volume was significantly improved by adding LVGLS, RVFWS and LAMD, but it was not significantly improved by adding LASr.
Conclusion: LAMD is a novel, reproducible and independent predictor of NOAA in patients with CA, being superior and incremental to other imaging predictors.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: The Amyloidosis Stakeholder Partnerships for Impact, Reach and Equity (ASPIRE), facilitated by Amyloidosis Research Consortium (ARC) brings together biotech and pharmaceutical companies with the shared goal of optimizing amyloidosis patient care. We present our research on current best practices and key barriers to patient-centric amyloidosis care at US Specialized Amyloidosis Centers (SACs).
Method: Teleconference interviews were conducted with 49 healthcare providers (HCPs: cardiologists, neurologists, hematologist-oncologists, nephrologists, advanced practice providers or registered nurses) from 19 SACs, 21 patients, 12 referring physicians and 3 patient advocacy representatives. SACs were selected based on geography, regional demographics, amyloidosis patient volume, years since establishment, and types of amyloidosis treated for a representative view of current amyloidosis care.
Results: We present the interim results of 26/49 HCPs from 13/19 SACs and 19/21 patients (see Figure).
SACs prioritize patient-centric multidisciplinary care, ensuring timely intake of new high-risk patients. Expanding local physician education was noted as critical to improving early diagnosis. Barriers to care noted by HCPs include patient distance to SACs, limited medical records and data sharing, and health inequity. From patients’ perspectives, travel burden, delayed diagnosis, and insurance hurdles were key challenges. Most SACs utilize metrics – which include but are not limited to internal and external registries, patient volume, and patient demographics – to measure progress in providing quality care.
Conclusions: Our interim results highlight the key barriers to care from amyloidosis HCPs’ and patients’ perspectives, with time and access to care prioritized by both groups.
Full results will be available at ISA 2024.
Copyright for this individual abstract is: © 2024 Putnam, Pfizer Inc., Alnylam. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Molecular diagnostics is essential in the diagnostic process of systemic amyloidosis.
We revised electronic records of molecular diagnostics for hereditary amyloidoses at the Pavia Referral Center for Systemic Amyloidosis between Jan-1998 and Dec-2023.
A total of 13,497 molecular tests in 7021 different subjects covering 14 genes were performed. A median of 2 genes were analyzed per subject (range: 1–9; IQR: 1–2).
The total number of performed tests, evaluated subjects and tested genes showed a progressive increase over time, with a first increment between 2004 and 2005 related to the discovery of an endemic focus of AApoAI caused by the p.Leu99Pro variant in Northern Italy, and a second increment after 2020, due to increased referral of patients with suspected AL or ATTR cardiac amyloidosis. Also, the proportion of presymptomatic tests for ATTRv has grown over the last few years reflecting increasing availability of effective therapies.
In total, we identified 79 different variants (including 9 previously unreported variants) in 1035 different individuals, with TTR and APOA1 accounting for 50.7% and 41.1% of cases, respectively. The number of different variants of clinical significance identified varied from 49 for TTR to 2 for GSN. One or few variants accounted for the majority of positive tests for TTR/APOA1/APOC2/LYZ, reflecting the presence of geographical clusters of hereditary amyloidoses caused by specific variants across the country.
Molecular diagnostics panels for hereditary amyloidoses need to continuously adapt to increasing demand and growing complexity, reflecting improved disease awareness, expanding number of pathogenic genes, potentially overlapping clinical phenotypes and geographic peculiarities.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: Cardiac Scintigraphy with Tc-99m labelled bone-seeking tracers has been transformative for the field of ATTR cardiac amyloidosis (CA) by facilitating a highly accurate noninvasive diagnosis. With the increasing application of this test in suspected cardiac amyloidosis, we sought to assess changes in referral patterns and test yield of Tc-99m PYP scintigraphy over time.
Methods: We conducted a retrospective analysis of clinical Tc-99m PYP scans from 2015 (year of first use) to 2023 at a single institution (Presbyterian Hospital, University of Pittsburgh Medical Center). Scans were performed as per the recommendations of the American Society of Nuclear Cardiology and interpreted for clinical use by a pool of 5 experienced readers. Annual rates of percent of positive scans were determined. The Cochran-Armitage test was used to determine if the proportion of positive tests changed significantly over the years studied.
Results: A total of 1005 PYP scans were performed during the analysis period. There was a progressive 8-fold increase in total scans performed from 23 scans in 2015 to 183 scans 2023. Scan yield was surprisingly constant over the 8-year period with average positivity of 28.1% ± 4.7% (range 21–6-38.3%). Figure 1 shows the percentage of positive and negative scans. There was no statistically significant change in positivity rate over the studied time period (p = .895).
Conclusion: Despite a dramatic increase in the utilization of Tc-99m PYP scintigraphy for suspected ATTR CA, the yield of testing has remained surprisingly constant in this single center experience.
Abstract
Topic: Pathology
The identification of amyloid fibril type is fundamental to determining treatment plans in patients with amyloidosis. Aside from those with ATTR amyloidosis who fulfil non biopsy criteria1, the gold standard is a histological diagnosis ideally of the affected organ2. In this study we analysed 874 endomyocardial biopsies by Congo red staining, immunohistochemistry and/or proteomic analysis performed at the UK NAC and describe the baseline characteristics for each amyloid subtype.
The fibril type identified was ATTR in 478 patients (54.7%), AL 218 (25.0%), No amyloid 145 (16.6%) and Other 33 (3.8%). Of the Other category; ApoA4 16 (48.5%), Unspecified 9 (27.2%), AA 3 (9%), ApoA1 2 (6%), ANP 2 (6%), AFib 1 (3%). 12 (1.4%) patients had ≥2 types identified.
highlights the baseline characteristics for each subtype. Of the patients with AL amyloidosis, 39 (17.9%) had a Kappa isotype and 177 (81.2%) a Lambda isotype, 2 were not evaluable. Only 21/218 (10.7%) of those with AL amyloidosis had a normal baseline sFLC ratio. In contrast 194/511 (38.0%) with non-AL amyloidosis had an abnormal sFLC ratio.
Table 1. Baseline characteristics of 874 endomyocardial biopsies at the UK NAC.
Those with AL amyloidosis vs. ATTR had a substantially higher median NT-ProBNP (5555 pg/mL vs. 2860.5 pg/mL, p < .001) and cardiac Troponin T (84 ng/L vs. 60 ng/L, p < .001) with a lower mean LV wall thickness (15 mm vs. 17 mm, p < .001) respectively.
Endomyocardial biopsy remains an important diagnostic modality for accurate identification of the fibril type, identification of rare and mixed amyloid sub-types, and exclusion of cardiac amyloidosis in the context of suggestive imaging.
Abstract
Topic: Diagnosis ATTRwt
A 68-year-old male was referred for evaluation of aortic stenosis (AS). His history included atrial fibrillation, bilateral carpal tunnel syndrome, and lumbar spinal stenosis. Two years prior, an echocardiogram showed mild AS. Repeat echocardiogram showed low-flow low-gradient severe AS, LVEF 40–45%, and grade III diastolic dysfunction. Coronaries were normal by angiography. He underwent aortic valve replacement (AVR) complicated by complete heart block requiring permanent pacemaker.
LVEF improved post AVR but worsened to 35–40% within 1 year and was initially suspected secondary to high ventricular pacing burden. Bi-ventricular pacer was placed and GDMT was titrated. A follow-up echocardiogram revealed moderate to severe cardiomyopathy; LV global longitudinal strain showed relative apical sparing pattern suggestive of cardiac amyloid. Biochemical tests were negative. Tc-99m pyrophosphate scan was strongly positive for cardiac ATTR amyloidosis (ATTR-CA) by quantitative and semiquantitative criteria. MRI showed diffuse contrast uptake within the myocardium consistent with cardiac amyloidosis. Genetic testing was negative. GDMT was discontinued and Tafamidis was started.
The prevalence of ATTR-CA is high in patients with AS and the coexistence of both conditions confers a worse prognosis. Prior to the diagnosis of AS, our patient had clinical features of amyloidosis, but the diagnosis was made several years after. Early identification of patients with severe AS at risk for ATTR-CA may allow prompt initiation of disease modifying therapy, treatment of associated comorbidities and discontinuation of therapies with no survival or symptomatic benefit. Implementation of diagnostic algorithms ATTR-CA at the time of AS diagnosis may lead to improved outcomes.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Background: Non-specific symptoms and other diagnostic challenges lead to underdiagnosis of cardiac amyloidosis (CA). Artificial intelligence (AI) could help address these challenges but a summary of the performance of these tools is lacking.
Methods: A narrative review of published literature describing (1) the performance of AI tools that use data from electrocardiograms (ECG) and echocardiography (ECHO) to improve identification of CA and (2) challenges that hinder adoption of these tools.
Results: Thirteen studies met inclusion criteria with sample sizes ranging from 50 to 2451 patients. Four studies used ECG data, eight used ECHO data and one used both. Most patients were males over age 60. The CA gold standard was typically defined as a CA diagnosis in an institutional or other database but the requirements for these diagnoses were heterogenous across studies, and many did not distinguish among CA subtypes. AI model development varied considerably, and only four studies included external validation. The ability of models to predict CA ranged from 0.71 to 1.00, sensitivity ranged from 16% to 100%, and specificity from 75% to 100%. Only one study reported model performance across strata of gender, age, race, and CA type. Persistent challenges to AI adoption include knowledge, trust, usability, cost, EHR/IT interoperability, patient-related factors, workflow, and strategic partnerships (see Table).
Conclusions: Published studies on AI for improved identification of CA show favorable performance measures but numerous methodologic and other challenges must be addressed before these tools should be widely adopted.
Copyright for this individual abstract is: © 2024 Pfizer Inc. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Treatments of ATTR
Background/Aim: Transthyretin (ATTR) amyloidosis is a rare, progressive disorder characterized by systemic ATTR amyloid deposition due to hereditary (ATTRv) or non-hereditary (wild-type [ATTRwt]) transthyretin protein instability. Dominant phenotypes include the heart (ATTR-cardiomyopathy [CM]), peripheral nerves (ATTR-polyneuropathy [PN]), or both (mixed). US ATTR amyloidosis prevalence is increasing, and true ATTRwt prevalence may be as high as 300,000, yet US-specific ATTR amyloidosis patient demographics and treatment utilization are not well-characterized.
Methods: This study used 2018–2020 data from Milliman’s Consolidated Health Cost Guidelines Sources Database (commercial – individual, small/large group) and the 100% Research Identifiable Files (Medicare Fee-for-Service [FFS]) from the Centers for Medicare and Medicaid Services (CMS) to characterize patients with amyloidosis. The population was segmented into genotypes and clinical phenotypes using ATTR-specific drugs (tafamidis, patisiran, inotersen), amyloidosis diagnosis codes, and diagnosis codes for cardiovascular and neurologic disease. Patients with evidence of primary amyloidosis, secondary amyloidosis, or non-segmented amyloidosis were excluded, yielding the ATTR amyloidosis cohorts.
Results: Patients with ATTR amyloidosis are covered by Medicare at a rate of 8:1 versus commercial. Patients with ATTRwt are predominantly male, while ATTRv is more evenly split. Except for ATTRv-CM, the average patient age is over 50. Patients with ATTRwt use ATTR-specific drugs more frequently than ATTRv patients.
Conclusion: Although all segments include patients who may not be candidates for treatment (e.g. asymptomatic or late-stage), only 8% to 36% of diagnosed patients receive any ATTR-specific drugs. The observed use of ATTR-specific treatments highlights the need for further investigation into factors driving treatment initiation and continuation.
Copyright for this individual abstract is: © 2024 AstraZeneca. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Bortezomib is a reversible proteasome inhibitor that is a mainstay of treatment of plasma cell disorders, including AL amyloidosis. Ocular toxicity is a rare side effect of bortezomib, and its clinical course has not been well described in AL amyloidosis patients.
Methods: We conducted an IRB approved retrospective, single institution study of all patients AL amyloidosis treated with a bortezomib-containing regimen from 2015 to 2022 who developed ocular toxicity. We excluded patients participating in a randomized clinical trial to avoid confounders.
Results: In total, we identified 12 patients and 10 required pharmacologic interventions. First line therapy was topical erythromycin ointment in 5 patients, oral doxycycline in 4 patients, and both in one patient. Of the five patients that started on topical therapy, only one patient had a complete resolution. Four of those patients failed treatment and required oral antibiotics. Subsequent therapy was oral amoxicillin-clavulanate in one patient and doxycycline in an additional three patients. For those that received doxycycline as their next line, both required long term (>8 weeks) doxycycline suppressive treatment to prevent additional styes with one patient adding in topical tobramycin-dexamethasone eye drops. For those treated with doxycycline as first line therapy, two patients were subsequently started on erythromycin ointment, one patient required the addition of oral amoxicillin-clavulanate, and one patient had complete resolution. Patients without suppressive therapy, had a shorter median time to resolution of 6.1 weeks as compared to 12.0 weeks.
Conclusions: Bortezomib-related ocular toxicities in amyloidosis can require multimodal therapy for resolution of symptoms.
Abstract
Topic: Diagnosis ATTRwt
Introduction: Despite new diagnosis and treatment options for cardiac amyloidosis (CA), guideline recommendations lack clinical uptake and CA remains underdiagnosed. To understand the barriers and challenges in diagnosis of CA, we sought to map the system of care that supports diagnosis of CA and to identify new implementation strategies to increase evidence-based CA screening practices.
Methods and Materials: Guided by System Evaluation Theory (SET), our research team conducted a stakeholder workshop with key subject matter experts (SMEs) to inform a systems map describing current and CA early diagnosis. We completed a qualitative matrix analysis of the workshop transcript to develop the map. We then conducted individual and small-group interviews with clinician workshop attendees to refine the map.
Results: Utilizing interview and workshop data, we mapped the patient’s journey from a pre-clinical stage through diagnosis. SMEs identified key clinical risk factors, clinical specialists, and necessary tests to complete the patient evaluation for suspected CA. They recommended 23 discrete strategies to increase the early detection of CA. These strategies covered preclinical testing, symptomatic evaluation, diagnostic evaluation, and those spanning entire spectrum of care.
Conclusion: Barriers to CA diagnostic testing relate to an uncoordinated and complicated healthcare system and a non-specific multisystem disease. System Evaluation Theory facilitated the identification of implementation strategies to improve diagnosis of CA. Future research calls for implementing and evaluating such strategies to improve adoption of evidence-based diagnostic practices.
Abstract
Topic: Basic Science ATTR
Introduction: Although hereditary transthyretin amyloidosis (ATTRv) is more frequent in the elderly population, it is not limited to older age groups. There are genetic variants that can lead to a more severe and earlier amyloidosis clinical presentation. We describe a series of cases with onset of symptoms under the age of 25 associated with the identification of a rare variant in the TTR gene.
Results: Three male patients from the same family with ATTRv confirmed by a positive molecular test for the p.F64S pathogenic variant, with a mean age at clinical presentation of 19 ± 3 years. The baseline characteristics of the patients are shown in Table 1. All the patients had a mixed phenotype, with severe polyneuropathy, dysautonomia and cardiomyopathy. All had left ventricular hypertrophy, with a mean septal thickness/posterior wall of 15.6 ± 4/13 ± 3 mm. One patient had recurrent large pericardial effusion. No deaths occurred during follow-up (5 years). All the patients received specific treatment for amyloidosis.
Discussion/Conclusion: We describe three relatives with a mixed and very early phenotype of ATTRv, determined by the p.F64S variant. This mutation is very rare, and we found 7 cases described in the literature, all very young, with a predominantly polyneuropathic phenotype, but most with associated heart disease. The p.V50M variant can also occur in young people, but this occurs around the third decade of life. In conclusion, amyloidosis should not be seen as a disease exclusive to the elderly population and should therefore be considered as a differential diagnosis for ventricular hypertrophy in young people.
Abstract
Topic: Basic Science AL
Background: Light chain amyloidosis (AL) is a disease marked by abnormal plasma cells (PCs) constitutively producing structurally aberrant monoclonal free light chains, which deposit in multiple organs including bone marrow (BM). Although AL shares several genetic characteristics and therapeutic treatments with multiple myeloma (MM), the possible effect of amyloidogenic monoclonal plasma cells and amyloid fibrils on the BM immune environment has not been fully characterized. Using single-cell mass cytometry analysis (CyTOF), the present study aimed to investigate the characteristics of immune cells and malignant PCs in the BM of newly diagnosed patients with untreated AL (n = 8) compared with the characteristics in healthy donors (HD, n = 5) and patients with untreated high-risk smoldering and newly diagnosed MM (n = 6).
Results: Supervised machine learning algorithm (CITRUS) and FlowSOM analyses showed that, when compared with HDs, the AL-BM showed significant upregulation of the antigen-specific suppressive TIGIT + CD8+ NKT-like cells (p = .014) (Figure 1A), an increase in exhausted PD-1 + (p = .047) and TIGIT + CD8+ T cells (p = .002), and down-regulation of promonocytes (p = .04). Conversely, no significant differences were found between MM and HD. Compared to MM, the AL-BM is significantly enriched in CD4+ central memory T cells (p = .035) (Figure 1B), but no differences were observed in specific PCs makers, including BCMA, CD38, CS1, and CD56.
Conclusion: Our preliminary data show that the BM of AL patients, but not MM patients, display a more prominent immune suppressive signature compared to HD. Understanding specific AL immune disruptions can offer insights into the disease and the potential for developing AL-directed strategies.
Abstract
Topic: Prognosis ATTR
Introduction: Atrial fibrillation (AF) poses a significant challenge in amyloidosis cardiomyopathy, particularly in transthyretin amyloidosis cardiomyopathy (ATTR-CM). With AF often being an initial symptom in ATTR-CM, it is vital to identify predictors for early intervention and prevention of thromboembolic events.
Purpose: This study aims to identify predictors for AF development in patients with ATTR-CM using data from the REACT registry.
Methods: The REACT registry, a retrospective cohort and multicenter study, enrolled patients with TTR mutation or wild-type. ATTR-CM diagnosis involved positive echocardiography and pyrophosphate scintigraphy, and, in some cases, cardiac or extracardiac biopsy. Binary logistic regression and multivariate analysis were employed, utilizing the LR backward method. ROC curve analysis and the Youden index determined optimal cutoff points for continuous variables.
Results: We included 273 patients with ATTR-CM diagnosis. The population, predominantly male (73.2%) with a median age of 73 years, showed a high prevalence of the ATTR variant (67.2%). Val142Ile was the most common variant (29.3%). AF prevalence was 25.2%. Binary logistic regression identified a left atrium diameter (OR 1.091, p = .005), and age (OR 1.052, p = .014) as AF predictors. ROC curve analysis established age ≥70 years and left atrium >45 mm as optimal cutoff points (AUC 0.643 and 0.727, respectively) (see figure 1).
Conclusions: In the Brazilian ATTR amyloidosis registry, the presence of a dilated left atrium >45 mm, and age ≥70 years emerged as predictors of AF, shedding light on crucial insights for early detection and management.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Cardiac amyloidosis is becoming increasingly recognized. Due to advances in imaging, namely Technetium Pyrophosphate Scintigraphy (PYP scan), the diagnostic algorithm has been simplified where biopsy of affected tissue is rarely needed. Early screening and appropriate treatment is pivotal to improve patient outcomes. However, screening of cardiac amyloid with a PYP scan is still quite low despite its recognized prevalence. We determined to look at which providers consider screening their patients with PYP imaging.
This was a single center retrospective data analysis looking at all the PYP scans ordered at the University of Minnesota and M Health Fairview from May 2019 (when the scan first became available for use) to 31 December 2023. 390 scans were performed overall, though only 254 were for clinical use, as 136 were for research purposes only. Of the 254 scans, a cardiology provider ordered 250 scans. Of the 4 scans ordered by non-cardiologists, 2 were from hematology and oncology, and two from hospitalist medicine.
Of the 250 scans ordered by cardiology providers, 102 were ordered by heart failure trained cardiologists, 87 by general cardiologists, 11 by interventional cardiologists, and 2 by electrophysiologists. Mid-Level advanced practice providers and trainees, within the cardiology division, ordered 42 and 7 scans respectively.
Education of amyloidosis to other specialties outside of cardiology, such as primary care, internal medicine, neurology, with empowerment to perform an evaluation for cardiac amyloidosis, is needed if the disease is going to be diagnosed at earlier stages.
Abstract
Topic: Diagnosis ATTRwt
Background: Prior studies suggest variability in cardiac amyloidosis (CA) detection across the U.S.
Research Question: Is there geographic variation in CA detection amongst U.S. Veterans in a contemporary cohort?
Method: This is a retrospective observational cohort study. CA was defined as ≥1 heart failure (ICD9/10) and ≥1 amyloidosis diagnosis. For geographic mapping the location was the state of the diagnosing Veterans Affairs (VA) facility. The population at risk was patients in each state with ≥1 VA encounter during the year. The outcomes were incidence and prevalence rates of CA at the state and U.S. Census regional level (per 100,000 patients). The data source was the VA Corporate Data Warehouse (MDClone ADAMS platform).
Results: The incidence and prevalence rates of CA by region are shown in the Table, and by state in the Figure. There was an increase in incidence and prevalence in all regions in 2012 and 2021. In both years, incidence and prevalence were highest in the Northeast and lowest in the South, with greater variation amongst black patients.
Conclusion: Despite increasing recognition of CA in the VA Health System, there is regional variation in incidence and prevalence in 2012 and 2021. VA facilities in the Midwest, West and especially the South may have differences in CA detection relative to those in the Northeast region, particularly with respect to black patients. Further research into health system, provider, and patient factors causing this variation is needed to ensure health equity and quality of care for patients with CA.
Abstract
Topic: Treatments of AL
Background: AL amyloidosis is a potentially fatal disease. In the ANDROMEDA trial, the addition of daratumumab to CyBorD backbone significantly improved hematological response (HR), organ response, and event-free survival (EFS). We performed a real-world study to investigate the efficacy of the addition of daratumumab to first-line therapy.
Methods: Single-center retrospective study of consecutive newly diagnosed AL amyloidosis patients seen between 2018 and 2022. Patients who received frontline daratumumab (with or without bortezomib) were compared to those treated with bortezomib-based therapy. For EFS analysis, an event was defined as death, hematological progression, end-stage cardiac or renal failure, or need for subsequent anti-plasma cell therapy in the absence of hematological progression.
Results: 333 consecutive patients were evaluated (daratumumab group =133, bortezomib group =200). The overall HR, complete response, and ≥ very good partial response at 2 months were better with daratumumab compared to bortezomib (91.3% vs 80.5%, p = .01; 15.9% vs 5.8%, p = .009; 62.7% vs 40.2 %, p = .0002, respectively). Overall cardiac response rate at 6 and 12 months was better in the daratumumab group (54% vs 32.1%, p = .01; 80% vs 56%, p = .009 respectively). There was no difference in the renal response at 6 and 12 months (51.1% vs 42.9%, p = .43; 53.3% vs 69.6%, p = .10 respectively). Daratumumab reduced the 3-month early death rate (6.0% vs 13%, p = .04). The two-year EFS and overall survival (OS) were significantly higher in the daratumumab group (Figure).
Conclusions: The addition of daratumumab to frontline therapy significantly improved HR and cardiac response, reduced early death rate, and prolonged EFS and OS.
Abstract
Topic: Imaging
Subtopic: Echo
Background: Increased left ventricular wall thickness (LVWT) often raises suspicion of cardiac amyloidosis (CA), with recent American Society of Echocardiography guidelines suggesting LVWT higher than 1.2 cm or relative wall thickness (RWT) higher than 0.42 as thresholds. The aim of this study is to explore the sensitivity of RWT compared to LVWT in patients with confirmed CA.
Methods: We conducted a retrospective analysis on patients with transthyretin (ATTR) or light chain (AL) cardiac amyloidosis at the Cleveland Clinic from 2006 to 2022 who had an echocardiogram within 6 months of diagnosis. Interventricular septal (IVST), posterior wall thickness (PWT) and left ventricular end-diastolic volume (LVEDD) were extracted. RWT was calculated as (IVST + PWT)/LVEDD.
Results: A total of 1688 patients were included. Median age was 67 for AL patients and 79 for ATTR patients. Abnormal IVST and PWT were found in 88% and 81% of patients, while 97% had RWT >0.42. A total of 138 patients (9%) had both IVST and PWT lower than 1.2 cm, but 97 (72% of these patients) still had abnormal RWT. Similarly, 1378 of 1389 (99%) patients with either increased IVST or PWT had a RWT above threshold. Finally, RWT remains extremely sensitive even in the absence of low voltage on EKG (96.5%).
Conclusions: While sensitivity of increased left ventricular wall thickness remains limited by variability of echocardiographic phenotypes, relative wall thickness may be a more reliable parameter for echocardiographic suspicion of cardiac amyloidosis.
Abstract
Topic: Diagnosis ATTRv
This study seeks to substantiate reports on serum neurofilament light chain levels (sNfl) as a diagnostic biomarker of ATTRv Amyloidosis. A comprehensive search on the PubMed database for relevant studies until January 2024. Human studies that contained baseline case-control data on sNfl in ATTRv Amyloidosis before treatment were included in the meta-analysis. The analysis compared sNfl levels in healthy subjects (HS) versus symptomatic ATTRv Amyloidosis patients (sATTRv), HS versus asymptomatic ATTRv Amyloidosis group (asATTRv), asATTRv versus sATTRv, and greater than I Polyneuropathy Disability (PND >1) score versus score I PND (PND I). The standard mean differences (SMD) at 95% confidence intervals (CI) were obtained using a random or fixed effects model of RevMan version 5.4.
A total of 589 sATTRv, 120 asATTRv, 67 PND >1, 45 with PND I score, and 4970 HS were meta-analyzed. The levels of sNfl were shown to be significantly higher in sATTRv than in HS (SMD =3.66, 95% CI: 0.99–5.73, PSMD =0.005), in sATTRv than in HS (SMD =1.77, 95% CI: 1.29–2.25, PSMD <0.00001), in PND > I than in PND I (SMD =1.39, 95% CI: 0.95–1.82, PSMD <0.00001), sNfl levels in HS and asATTRv yielded insignificantly negative SMD in asATTRv than in HS (SMD = −0.18, 95% CI: −1.12–0.76, PSMD =0.71) pointing to the fact that sNfl levels is a potent biomarker for early diagnosis of ATTRv Amyloidosis before symptoms of polyneuropathy manifest.
This study confirms sNfl as a potent biomarker for early diagnosis of ATTRv Amyloidosis; however, studies with larger sample sizes are needed to pave the way for an updated analysis.
Abstract
Topic: Diagnosis AL
Background: Multiple myeloma primarily affects the bone marrow (BM), resulting in bone lesions and BM failure. In contrast, amyloidosis primarily impacts organs and tissues due to the deposition of amyloid proteins. The gradual proliferation of plasma cell clones in the BM leads to the secretion of unstable immunoglobulin-free light chains (FLC), which infiltrate peripheral tissues, causing significant organ damage. The clinical presentation of amyloidosis is often nonspecific. Here, we present an atypical case involving heart failure with preserved ejection fraction, along with an association of MM and amyloidosis, suspected by low voltage at electrocardiogram and ‘hypertrophy’ (Figure 1A),
Clinical Case: A 62-year-old woman with a history of recent breast cancer treatment presented with chronic musculoskeletal pain, bilateral carpal tunnel syndrome, biceps tenosynovitis, changes in bowel habits, periorbital ecchymosis, dyspnea, anasarca, and worsening renal function. Investigation revealed multiple myeloma confirmed by BM biopsy (plasmocytoma). Recurrent pleural effusion (Figure 1B) necessitated local biopsy, confirming amyloidosis with positive Congo red staining (Figure 1C). Liquid chromatography coupled to ultra-resolution tandem mass spectrometry detected a peptide profile consistent with LAMBDA-type immunoglobulin light chain, the amyloid deposit protein. Abdominal fat biopsy also confirmed free light chains (Figure 1D). The patient is undergoing treatment with daratumumab-CyBorD.
Conclusion: AL amyloidosis is a systemic disease, and diagnosing amyloid protein deposition guides appropriate treatment, improving prognosis. Each biopsy opportunity providing documented amyloid protein is invaluable for tailored management.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: Diagnosis of hereditary cardiac amyloidosis remains challenging. 124I-evuzamitide (124I-p5 + 14, AT-01), a novel pan-amyloid radiotracer, accurately detects cardiac involvement in light-chain and wild-type transthyretin amyloidosis. However, its ability to detect cardiac involvement in rare forms of amyloidosis has not been well studied.
Objectives: To compare myocardial uptake of 124I-evuzamitide in rare forms of amyloidosis with or without cardiac involvement and in controls.
Methods: We included 20 participants: 7 with hereditary amyloidosis (2 AApoAI, 1 AApoAIV, 1 ATTRv p.L78H, 2 ATTRv p.T80A, 1 ATTRv p.V142I), 1 with localized pulmonary light-chain amyloidosis and 12 controls without amyloidosis. All participants underwent positron emission tomography/computed tomography (PET/CT) 5 h after injection of 124I-evuzamitide (median administered activity 0.97 mCi). We assessed all scans visually and measured myocardial radiotracer activity above blood pool as left ventricular percent injected dose (LV %ID = [mean activity concentration / injected activity] x activity volume).
Results: All participants with hereditary amyloidosis had myocardial uptake on visual assessment, but the participant with localized amyloidosis and controls had no myocardial uptake. Median LV %ID was 1.6197 (IQR 0.6783–2.1057) in hereditary amyloidosis, 0.0001 in localized amyloidosis, and 0.0027 (IQR 0.0007–0.0093) in controls (overall p < .001). For both AApoAI participants, echocardiogram, and magnetic resonance imaging (MRI) showed no signs of cardiac involvement, but PET/CT demonstrated myocardial 124I-evuzamitide uptake (Figure).
Conclusions: 124I-evuzamitide PET/CT can detect cardiac involvement in multiple types of hereditary amyloidosis, even when the echocardiogram and MRI are negative. Furthermore, 124I-evuzamitide PET/CT appropriately shows very low, non-myocardial uptake in localized amyloidosis and in controls.
Abstract
Topic: Imaging
Subtopic: Radionuclides
Background: 124I-evuzamitide (124I-p5 + 14, AT-01) is a novel pan-amyloid radiotracer for positron emission tomography/computed tomography (PET/CT). It can quantify cardiac amyloid burden in multiple types of amyloid cardiomyopathy. However, its ability to measure temporal changes in cardiac amyloid burden is unknown.
Objectives: We aimed to measure temporal changes in cardiac amyloid burden in patients with light-chain or wild-type transthyretin amyloid cardiomyopathy (AL-CMP, ATTRwt-CMP).
Methods: We included 9 participants: 2 with AL-CMP and 7 with ATTRwt-CMP. At baseline and 12 months, all participants underwent PET/CT 5 h after injection of 124I-evuzamitide (median injected activity 1.08 mCi). Cardiac amyloid burden was quantified using myocardial radiotracer activity above blood pool as left ventricular percent injected dose (LV %ID = [mean activity concentration / injected activity] x activity volume).
Results: All participants with AL-CMP were in hematological remission after therapy and all participants with ATTRwt-CMP were treated with tafamidis. At baseline, the median LV %ID was 2.08 (IQR 1.67–2.40) and at 12 months 2.16 (1.49–2.88, p = .734). The median absolute change in LV %ID over 12 months was +0.04 (-0.09 to +0.12), corresponding to a relative change of +1% (IQR -6% to +7%), with a range of -18% to +25% (Figure).
Conclusions: 124I-evuzamitide PET/CT can capture temporal changes in cardiac amyloid burden. In line with the expected effect of therapy for AL or ATTR amyloidosis, no significant changes in myocardial uptake were observed at 12 months. However, 124I-evuzamitide PET/CT detected a wide range of individual temporal changes, suggesting measurement variability or heterogeneity of response to therapy.
Abstract
Topic: Treatments of ATTR
Background: Identifying markers of therapeutic futility may help to channel expensive therapy and finite resources appropriately.
Methods: We sought to determine the predictors of all-cause death occurring within 12 months of initiating tafamidis therapy using real-world, individual-level patient data pooled from 5 expert amyloid centers (Cleveland Clinic Foundation, University of Pittsburgh, Columbia University, Saint Luke’s Mid-America Heart Institute, Oregon Health Sciences University)
Results: Of 624 patients studied, 65 (11%) died within 12 months of starting tafamidis therapy. Patients who died were older [age (median, IQR) 79, 73–85 vs. 77, 71–83 p = .037)] had a greater prevalence of NYHA III (69.7% vs 29.7%, p < .001), NYHA IV (7.7% vs 0.2%, p < .001), hypertension (81.5% vs 69.2% p = .054), lower LVEF (43.5% vs 55%, p < .001), higher NAC stage (p < .001), and higher diuretic usage (furosemide score 3, 38.5% vs 11.3%, p < .001). Sex, race, diabetes mellitus, concomitant CAD, and variant ATTR were not predictive of early mortality. In multivariable analysis, NYHA class III or IV, a high daily diuretic dose, LVEF, and NAC stage >0 were independently predictive of early mortality.
Conclusion: Routinely obtained clinical parameters can predict early mortality after tafamidis initiation in ATTR amyloid cardiomyopathy. Further analysis is being performed to determine the feasibility of a clinical score to predict the futility of tafamidis therapy in these patients.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: Myocardial toxicity from amyloidogenic light chains (aLCs) and architectural distortion from amyloid fibril deposition contribute to cardiac dysfunction in AL. Our transcriptomic analysis highlighted dysregulation of contractility in cardiomyocytes exposed to aLCs so we hypothesized that there could be clinically measurable differences in echocardiographic global longitudinal systolic strain (GLS).
Methods: Of 426 cardiac AL patients seen at Boston University Amyloidosis Center between 2011 and 2023, 29 patients had presumed LC-toxicity based on: (1) elevated cardiac biomarkers (BNP >81 pg/mL or NT-proBNP >899 pg/mL or troponin I >0.033 ng/mL, per institutional reference ranges); (2) echocardiographic interventricular septal diameter in diastole ([IVSd] < 11 mm in males and <10 mm in females); (3) eGFR >60 mL/min/1.73 m2; and (4) no late gadolinium enhancement on cardiac magnetic resonance imaging (if performed). GLS was post-processed manually (n = 16) by one observer using TomTec 2D CPA. Median follow-up was 9.16 years (range 6.17–11.67). Overall survival (OS) was evaluated using Kaplan-Meier and log-rank tests.
Results: Among patients with presumed LC-toxicity, 72% (n = 22/29) had BU cardiac stage II and 28% (8/29) had stage III disease (Table 1). Eighty-one percent (13/16) had abnormal GLS. OS was similar between patients with LC-toxicity and increased IVSd among BU cardiac stage II disease.
Conclusions: A subset of AL patients demonstrate cardiac dysfunction as evidenced by abnormal GLS and increased cardiac biomarkers despite normal IVSd; this we postulate to mainly result from the myocardial toxic effects of aLCs. OS by BU cardiac stage was similar to patients with increased IVSd.
Abstract
Topic: Diagnosis ATTRv
Despite the use of multimodal testing, the diagnosis of cardiac amyloidosis can be challenging and requires a high index of suspicion. We present a rare case of cardiac amyloidosis without significantly increased left ventricular (LV) wall thickness which was identified on endomyocardial biopsy during left ventricular device (LVAD) implantation.
A 77-year-old male presented to our center from an outside hospital with initial diagnosis of ischemic cardiomyopathy following percutaneous coronary intervention to the left circumflex artery (Lcx). Initial cardiac magnetic resonance imaging (cMRI) demonstrated scar in the Lcx territory without increased LV wall thickness. Electrocardiogram with normal voltage, sinus rhythm and premature ventricular contractions. The patient progressed to end-stage heart failure, and LVAD was placed. Prior to implantation, echocardiogram demonstrated a mildly thickened LV wall at 11 mm with average global longitudinal strain of −2% and relative apical strain of 0.56, not suggestive of amyloid.
Apical core biopsy during LVAD implant suggestive of amyloid light chain amyloid, however subsequent testing was negative for monoclonal protein. Biopsy was sent for laser microdissection with liquid chromatography-mass spectrometry (LC-MS) identifying transthyretin amyloidosis. The patient was started on Tafamidis, and his diagnosis informed genetic counseling for his family.
This patient’s presentation was non-classical on multiple tests: echocardiogram, electrocardiogram and cMRI. At 11 mm, his LV was less than current AHA/ACC/HFSA guideline of 14 mm when considering amyloidosis. This patient did have other indications of amyloidosis including bilateral carpal tunnel syndrome and history of ventricular tachycardia. This case highlights the complexity of identifying cardiac amyloidosis despite contemporary diagnostics.
Abstract
Topic: Diversity Equity Inclusion
The 3 most common Transthyretin Amyloid subtypes are ATTRwt, TTR V30M, and TTR V122I. A comprehensive search of the PubMed database until May 2023 was performed. This review contains an overview of 399 original studies of ATTRwt, TTR V30M, and TTR V122I with details of annual study distribution of all the original studies and only case reports for the past 28 years, first author affiliation locations by country in which 31 countries are involved, which only 10 recorded at least 11 original studies each, where the United States of America (USA) leads with 103 study reports, followed by Japan with 50 study reports being 48.5% of the studies of the USA, while the remaining 21 countries has a high of 6 studies and a low of 1 study. An analysis of continental study contributions showed that the European continent recorded the highest with 214 studies, followed by South America, which recorded the second highest count of 108, about 50.4% of the records from the European continent. The third, fourth, and fifth highest continental records are Asia, North America, and Oceania, respectively, with Africa having no record. Thus, there is no first original study with an affiliated institution in Africa. Furthermore, of the 399 original studies, 61 are from 17 Amyloidosis centers, with the UK National Center of Amyloidosis recording the highest of 20 of 61 original publications.
This report is expected to encourage and foster collaboration and support programs for countries and continents lagging in original research in ATTR Amyloidosis.
Abstract
Topic: Prognosis AL
Aim: Patients with systemic AL amyloidosis and cardiomyopathy (AL-CMP) have significant functional limitations. This study aimed to quantify 6-min walk distance (6MWD) at baseline (treatment initiation), 6 and 12 months, quantify its changes following therapy, and assess its prognostic value in AL amyloidosis.
Material and methods: Patients with recently diagnosed, biopsy-proven AL amyloidosis, were enrolled in a prospective study (clinical trials.gov NCT02641145) and categorized into AL-CMP (abnormal cardiac serum biomarkers) or AL-non-CMP (normal cardiac serum biomarkers and normal LV wall thickness). 6MWD was measured at baseline, 6 and 12 months in AL-CMP, or at baseline and 6 months in AL-non-CMP. Data were compared using Wilcoxon rank-sum test and Wilcoxon signed-rank test (paired). Kaplan-Meier analysis and the log-rank test were used to assess survival (all-cause death).
Results: This study included 81 participants: 61 AL-CMP (75%) and 20 AL-non-CMP (25%). Median age was 61 years (interquartile range [IQR] 57–67 years) and 46 were males (57%). Among participants, 41 AL-CMP (67%) and 18 AL-non-CMP (90%) underwent ≥1 follow-up visit. In the AL-CMP cohort, 22 (27%) died during a median follow-up of 42 months. At baseline, median 6MWD was 308 m (IQR 0–420) in AL-CMP and 462 m (IQR 390–517) in AL-non-CMP (p < .001), with significant improvement at 12 months in AL-CMP (Figure 1A). Lower baseline 6MWD predicted worse survival (Figure 1B).
Summary and conclusion: Patients with AL-CMP have severely limited 6MWD compared to AL-non-CMP. 6MWD improves at 12 months after treatment initiation in AL-CMP. 6MWD at baseline is a strong predictor of worse survival.
Abstract
Topic: Patient Reported Outcomes/Quality of Life
Background: Amyloidosis often results in cardiomyopathy. With gastrointestinal involvement, the disease burden rises. This study probes the impact of amyloidosis on caregiver burden and focuses on the role of gut involvement.
Methods: 12 caregivers of cardiac amyloidosis patients (11 ATTR, 1 AL) from a tertiary program were assessed using three validated instruments: the Bakas Caregiving Outcomes Scale and the Oberst Caregiving Demand and Difficulty sub-scales. Gastrointestinal amyloid was identified via Congo red staining on biopsy samples in a subset of these patients.
Results: The average age of caregivers was 67.9 years. 50% were employed, and 75% were married. The average duration of caregiving was 16.5 months. Using the Bakas scale, findings showed reduced social activity, decreased energy, and compromised stress tolerance. The Oberst Difficulty scale indicated 67% faced increased chores, while the Oberst Demand scale highlighted 75% with greater transportation needs. A majority of caregivers monitored symptoms and provided emotional support. While PYP Grade on pyrophosphate scintigraphy was not linked to caregiver strain, the presence of gastrointestinal amyloidosis was. A trend also suggested that extended caregiving duration correlated with a heightened burden [Figure 1].
Conclusion: Cardiac amyloidosis poses varied challenges for caregivers, from logistical hurdles to emotional stresses. Notably, there appears to be a correlation between increased gastrointestinal involvement, length of care, and caregiver burden severity. Given the complexity of amyloidosis, caregiver support is vital. Furthermore, early screening and detection of gastrointestinal disease can offer relief to both patients and caregivers.
Abstract
Topic: Treatments of AL
Light chain amyloidosis is caused by plasma cell neoplasia. Though unproven, presumably a complete eradication of such would represent the cure. Unfortunately, this state is not measurable today. However, pursuit of this goal by estimation may be a reasonable strategy for some patients, in the absence of a better alternative.
Here we present the case of a 38-year-old patient who achieved approximately a 100× reduction in monotypic plasma cell burden by next generation sequencing, from 50/million to below the limit of detection of 1/million (but still positive, indicating a count of 1–3 monotypic cells in the sample of 3.2 million). Extrapolating very roughly from a 10cc sample to the patient’s entire red marrow volume, we might say that this represents a total MRD of 10,000 then 100 monotypic cells, respectively.
This 100× reduction in plasmacytosis was achieved over a 3-month trial of daily venetoclax with weekly bortezomib and methylprednisolone. Assuming continuation of a logarithmic decay, we posit that repetition of this treatment could result in a presumed total MRD of 1 monotypic cell, then 10–2, 10–4, etc. The patient is currently in the second repetition and is tolerating the treatment well with plans to continue to a presumed total MRD near zero.
Abstract
Topic: Prognosis AL
Background: There is a constant need for the identification of novel biomarkers that could efficiently improve risk stratification in AL amyloidosis. In this study we evaluated the prognostic impact of circulating tumor cells (CTCs) in previously untreated patients with AL amyloidosis, which has correlated with adverse clinical outcomes in multiple myeloma. Methods: The presence of CTCs was assessed with next generation flow cytometry (NGF) in 179 consecutive patients at diagnosis, according to Euroflow guidelines. The same approach was used for the assessment of minimal residual disease (MRD) in patients achieving hemVGPR/hemCR ≥6 months post treatment initiation. The median follow-up was 24 months (range: 6–72 months).
Results: With a median limit of detection reaching 2.2 × 10−6, CTCs were detected in 106/179 (59%) patients with a median value of 0.0015% of total nucleated cells. The absence of CTCs correlated with lower LDH levels(p = .001), NTproBNP(p = .007), dFLC(p = .01) and BM infiltration(p < .001); there was no correlation with organ involvement patterns. Regression analysis did not show correlation between baseline CTCs and probability or time to CR achievement. However, patients with detectable CTCs had a 4.2-fold higher risk of not reaching MRD negativity (p < .0001). Patients with CTC levels ≥10–3 (n = 15, 8.4%) had poorer outcomes with a median OS of only 15 months (HR: 2.4, 95% CI: 1.2–5.1, p < .01).
Conclusion: NGF allows for the detection of CTCs in the majority of patients with AL amyloidosis, the presence of which is associated with adverse prognostic features and a lower probability of achieving deep hematologic responses.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Introduction: ATTRv-neuropathy is a progressive disease whose prognosis changed by recently introduced medications. In this context it is important to have an easy instrument to measure disease progression.
Objective: to describe a practical protocol to evaluate the manifestations of ATTRv-neuropathy.
Proposed protocol: based on the pivotal studies, we established an informatized, quantitative protocol to evaluate strength, sensation, dysautonomia and neurophysiological parameters. Pain and tactile abnormalities were graduated considering 39 regions. Each affected region scores 1 point. Vibration and posture were graduated according to 6 regions. We used the visual analog scale for pain and presence of sensory ataxia. We assessed postural hypotension, and 42 other autonomic manifestations. MRC graduated strength, considering 38 regions. Neurophysiological indices: SNAP amplitudes of ulnar and sural nerves; CMAP of peroneal and ulnar nerves; presence of the SSR; and RR interval with deep breathing and Valsalva.
Rather than a global sum score of the individual parameters, we compared individually each of the individual items in sequential visits. This comparison can be displayed in graphic and table formats.
Results and conclusions: the described protocol is now in validation. We think it may be a sensitive method able to identify clinically meaningful changes from pre-symptomatic to symptomatic status and also to identify early responders vs non-responders. As it reflects the neurological evaluation, we believe it will be a valuable instrument to monitor following patients with sensory, motor, and autonomic neuropathies.
This study is sponsored by PTC.
Abstract
Topic: Diagnosis ATTRwt
Background: Transthyretin amyloidosis (ATTR) prevalence continues to rise due to increased recognition and improved diagnostic techniques. Non-biopsy diagnostic criteria, utilising cardiac bone scintigraphy (BS), has facilitated this, however up to 30% require histopathological confirmation. Histopathological diagnosis is limited by local expertise in biopsy procedures, immunohistochemical assessment, and mass spectrometry access. Off-target biopsy ATTR diagnostic rates remain poor. Patient factors, including anticoagulation and frailty, and limited access to quaternary centres makes endomyocardial biopsy (EMBX) challenging, hence alternate on-target sites require consideration. We review our centre’s use of non-biopsy criteria, and on- and off-target biopsies for ATTR diagnosis.
Methods: All patients referred to St Vincent’s Amyloid Clinic between January 2022 and 2024 were reviewed. Patients were included if ATTR was suspected on histopathology and/or BS. Patients with incomplete work-up or known alternate amyloid subtype were excluded.
Results: Of 149 patients, 85 suspected ATTR cases were reviewed. Mean age was 79 ± 9 years, 11 female (13%). All had PYP BS, echocardiography and standard assessment to exclude AL. ATTR was diagnosed in 84 (43 ATTRwt, 5 ATTRv, 37 pending/declined genetics), EMBX and repeat BS reclassified one as restrictive cardiomyopathy. Non-invasive diagnostic criteria was met in 60.7%(51). On-target biopsy confirmed diagnosis in 31%; 13 EMBX, 8 tenosynovial, 2 bowel, 1 lung, 1 bladder. Five patients await tenosynovial biopsy results. Off-target biopsy was non-diagnostic in all attempted cases (4 salivary gland, 3 fat-pad).
Conclusion: Our study demonstrates the diagnostic challenges of ATTR. Histopathological confirmation remains necessary in a significant population and alternative biopsy sites require consideration, especially in high-risk patients or with limited EMBX access.
Copyright for this individual abstract is: © 2024 Copyright of the Crown in Australia. Published by Informa UK Limited trading as Taylor & Francis Group on behalf of the International Society of Amyloidosis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Abstract
Topic: Treatments of AL
Background: For patients with relapsed/refractory multiple myeloma (MM), B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T-cell (CAR-T) therapy has emerged as an innovative solution, but its efficacy with concomitant cardiac amyloidosis is less understood.
Case: The patient was diagnosed with light chain (AL) amyloidosis and MM at age 50, complicated by cardiac (Mayo Stage IV) and pulmonary involvement. Over 14 years, he underwent eight lines of treatment including two autologous hematopoietic stem cell transplantations. He ultimately received treatment with 0.6 × 108 CAR-Ts per kilogram of ciltacabtagene autoleucel after lymphodepletion chemotherapy. Complications included grade 2 cytokine release syndrome with brief atrial fibrillation that resolved, and delayed neurotoxicity characterized by parkinsonism symptomatology which was successfully treated with intrathecal chemotherapy. At 3 months post-infusion, the patient achieved a deep hematologic response (measurable residual disease negativity <10–6). Cardiovascular magnetic resonance (CMR) 4 months post-infusion demonstrated stable near-transmural involvement of amyloidosis compared to 4 years prior. By 7 months, the patient remained in stringent complete response, did not require diuretics, and remained free of heart failure hospitalizations and neurologic symptoms.
Conclusion: We describe a patient with MM and cardiac AL amyloidosis who experienced an optimal treatment outcome with BCMA CAR-T therapy and mild improvement in heart failure. While CMR showed stable amyloidosis 4 months after treatment, a longer timeline to observe disease regression is suggested. This case underscores the use of BCMA CAR-T therapy not just as a definitive treatment of MM, but also as a promising option for AL amyloidosis with cardiac involvement.
Abstract
Topic: Prognosis/Natural History Other More Rare Amyloidoses
Background: Breast amyloidosis is uncommon, and little is known about its clinicopathologic and proteomic features.
Aim: To evaluate the clinicopathologic and proteomic features of breast amyloidosis.
Material and methods: The demographic and proteomic features of all Congo red-positive breast tissue specimens typed by a clinical proteomics-based amyloid typing assay (LC-MS/MS) in the Mayo Clinic reference laboratory between August 2008 and December 2023 (n = 36,864) were reviewed (n = 450). Clinical information was available for 29 patients.
Results: Average age was 66.9 years with female:male ratio of 55:1. The vast majority (n = 435, 97%) were immunoglobulin-associated and included AL-lambda (n = 247, 57%), AL-kappa (n = 168, 39%), and AH (n = 20, 5%). Other amyloid types included AA (n = 7; 2%), ATTR (n = 4, 1%), AIns (n = 1), AFuz (n = 1), AGel (n = 1) and ALac (n = 1). We detected amino acid abnormalities indicative of known amyloidogenic mutations (V122I and L107V) in 2 ATTR cases (2/4, 50%). 11/19 (58%) AL patients who had monoclonal protein studies performed had an M-spike. Of the 9 patients with an M-spike for whom cardiac information was available, 8 (89%) had no cardiac involvement and the remaining case was equivocal. 27/29 (93%) were alive at last follow-up (median =4.9 months, range =2.1 to 170.1 months).
Summary and conclusion: Breast amyloidosis typically occurs in older women. The vast majority are immunoglobulin-associated, but other types can occur in this site. Although the presence of an associated M-spike is common, associated systemic amyloidosis is rare. These findings suggest that breast amyloidosis is usually immunoglobulin-associated and is commonly a localized phenomenon.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: In January 2021, the AMILO-LATAM research group was created to study the current prevalence of transthyretin cardiac amyloidosis (ATTR‐CA) in Latin America (LA), the degree of knowledge, its diagnosis and management among physicians, and promote registries and guidelines based on evidence and regional needs.
Methods: In the first two surveys (n = 488), we identified gaps in LA doctors’ knowledge about the disease, its diagnosis and treatment, the poor use of non-invasive imaging methods, and the need for technological infrastructure. We created a work plan to improve knowledge, resource use, and diagnosis conditions.
In 3 years, we participated as speakers at more than 40 international conferences, presented five posters, and published four publications. In collaboration with ASNC, we held two free webinars (606 attendees from more than 35 countries). We created a Latin American Network of Nuclear Medicine Services to diagnose ATTR-CA in 113 centers in 18 LA countries. We carried out the same initial survey as a follow-up almost 3 years later. The information was automatically entered into a spreadsheet.
Results: We observed a significant improvement in knowledge about ATTR-CA, better identification of the red flags, and mayor correct use of imaging methods for non-invasive diagnosis.
Conclusion: We worked with educational programs, webinars, congress participation, and other measures to increase clinical awareness, which had a favorable impact on reducing the knowledge gap on ATTR-CA in LA. The red flags are clearer, and more PYP studies are requested, favoring the timely diagnosis of the disease.
Abstract
Topic: Diagnosis Other More Rare Amyloidoses
Introduction: Amyloidosis is a rare disease characterized by the deposition of abnormal proteins in extracellular tissues. It presents systemic or localized involvement of different organs. Pulmonary amyloidosis is a common target of amyloidoses and presents with 3 different types of patterns: diffuse alveolar-septal, nodular, or tracheobronchial. Nodular pulmonary amyloidosis is a subtype that can mimic other lung conditions that present with pulmonary nodules, such as metastasis, sarcoidosis, and tuberculosis. It is usually associated with AL amyloidosis but may be associated with monoclonal lymphoproliferative and auto immune disorders.
Case report: We report a 56-year-old woman with a history of weight loss, shortness of breath upon exertion, small joint arthritis and dryness of the mouth and eyes. A chest computed tomography revealed bilateral pulmonary nodules giving the impression of a neoplastic nodule. A histopathological examination of biopsied lung tissue confirmed a diagnosis of nodular pulmonary amyloid. No monoclonal protein was identified, and mass spectrometry detected a large amount of heavy and light chain immunoglobulins, making it impossible to characterize the amyloidogenic deposit. The patient showed positive antinuclear, anti-Ro and anti-LA antibodies and was clinically diagnosed with primary Sjögren's syndrome.
Discussion: Pulmonary amyloidosis presents a broad clinical and etiological spectrum. Although rare, nodular pulmonary amyloidosis should be included in the differential diagnosis of pulmonary nodule. It is mandatory the evaluation of associated conditions such as malignancy and autoimmune disorders. Histopathological analysis is crucial. This case demonstrates pulmonary nodular amyloidosis as a trigger for investigation and diagnosis of a rare association with Sjogren syndrome.
Abstract
Topic: Diagnosis ATTRwt
Our study aimed to increase suspicion for transthyretin amyloidosis (ATTR) among cardiologists leading to increased screening for amyloidosis.
Patients at risk for amyloidosis were retrospectively identified via chart review showing increased left ventricular wall thickness, intact systolic function, advanced age, and heart failure. A list of patients and instructions for ordering amyloidosis testing was given to cardiologists to determine if further evaluation was warranted. The number of Technetium 99m-Pyrophosphate (PYP) scans and ordering physicians before and after this intervention were recorded.
The algorithm identified 349 potential high-risk patients. 28 months prior to protocol initiation, PYP scans were ordered for 22 patients with 6 being equivocal or positive. During this project, 142 PYP scans were ordered, with 18 being equivocal or positive. The number of ordering providers increased from 7 prior to 22 by the end of this project within 24 months. Change point analysis noted on PYP scan ordering patterns noted a statistically significant difference in the total amount of PYP orders after protocol initiation (regression coefficient 1.27 vs 6.31, p < .001), as well as the amount of equivocal or positive tests (regression coefficient 0.38 vs 0.52, p < .01).
The results suggest that increasing awareness of patients at risk for ATTR increases the number of providers who screen, total number of PYP scans ordered, and identification of patients with equivocal or positive PYP scan results. Early and accurate diagnosis of ATTR is imperative as new therapies such as TTR silencers and TTR stabilizers can optimize cardiac function and symptom management.
Abstract
Topic: Basic Science AL
Senile amyloidosis in mice has been described as an APOA2 amyloidosis mostly associated with the type C APOA2 (APOA2c). We observed that transgenic mice with a knockout of Serpine-1, the gene encoding for Plasminogen Activator Inhibitor-1 (PAI-1) developed amyloidosis, starting at 12–18 months of age, affecting kidney, liver, spleen and to a lower extent, heart. PAI-1 has an important role in hemostasis through the regulation of plasmin activity. The objective of this study is to characterize this new senile amyloidosis model. Mass spectrometry indicates that APOA2 is the major component of deposits. Electron microscopy on organs and AFM identifies typical amyloid fibrils. Western Blots and MS on purified fibrils confirmed the presence of the full-length mature form of APOA2 together with other amyloid protein signature such as ApoE and Vitronectin. PAI-1-/- mice express the non-amyloid APOA2a allele. Seeding with APOA2 fibrils accelerated amyloid formation. Albuminuria appeared to be correlated with the extent of amyloid deposits in the kidneys and can be to use to follow pathology development. Compared to C57/Bl6 mice, also known to occasionally develop ApoA2 amyloidosis with age, penetrance of amyloidosis is 100% in PAI-1-/- mice and starts at earlier age.
Altogether, we described a new mouse model of systemic APOA2 amyloidosis which mimics multiple organ damages, is easily inducible and can be monitored through kidney function. Hence, it could represent an exquisite amyloidosis model for pre-clinical trials. Further studies are needed to understand the link between the absence of PAI-1 and APOA2 amyloidosis in this model.
Abstract
Topic: AI/Electronic Records to Facilitate Diagnosis
Background: We developed an artificial intelligence electrocardiogram (AI-ECG) algorithm to predict the presence of CA. PREDICT-AMY is a randomized two-arm intervention trial that randomizes providers to intervention (receipt of alert on positive AI-ECG score and suggested further diagnostic testing) or control (no alert, usual care) arms. The results of these diagnostic tests are incorporated into enhanced AI-based models to increase CA detection predictive value.
Goal: To explore patient and provider-related factors associated with data availability for these enhanced model calculations in the intervention arm of the study.
Methods/Results: 933 patients with positive AI-ECG scores are included. 83% of patients in the intervention arm had data to calculate at least one enhanced model using non-ECG data. Neither sex nor age were associated with a higher probability of having a calculated enhanced model compared to men (). In contrast, >1 ECG available and >1 AI-ECG score suggestive of CA in the past 6 months and lower eGFR increased the probability that sufficient additional testing was done to calculate an enhanced model. Next, we compared providers in the intervention arm (n = 47) based on whether certain characteristics predicted sufficient testing to generate > =1 enhanced model for their patients. There was no difference in provider age, sex, or practice years. There was a trend for cardiologists to be above the median of model completeness for at least one patient compared to hematologists (p = .1).
Table 1 Patients’ characteristics associated with the use of enhanced AI-based models to detect cardiac amyloidosis.
Conclusion: We demonstrate that our advanced models are feasible in the clinic and their use does not exceed usual practice.
Abstract
Topic: Prognosis ATTR
Background: From clinical experience and clinical trials, it is apparent that patients with ATTR cardiac amyloidosis (ATTR-CA) are being diagnosed earlier and with less severe disease, than those seen a decade ago. Yet, this remains a disease of aging, hence, frailty is an important consideration in ATTR-CM. Frailty adversely affects outcome in many diseases. We therefore sought to determine the proportion of patients in a contemporary population referred to an amyloidosis program who meet criteria for clinical frailty.
Methods: 116 unselected patients with proven ATTR-CM underwent the Short Performance Physical Battery (SPPB) and standard clinical evaluations. The SPPB consists of a brief series of physical tests assessing balance, gait speed and unassisted standing from a chair, and is scored from 0 to 12 with a score of 8 or lower indicative of frailty.
Results: 45 patients (38.8%) were found to have a SPPB score <8, indicative of frailty. Those with a low SPPB had higher rates of atrial fibrillation/flutter or a paced rhythm (12/71 v 22/45. p = .02), and higher NT-proBNP (median 1170 (560–2459) pg/mL v. 1977 (970–3197) pg/mL. p = .024). Global longitudinal strain, a marker of cardiac function, did not differ between groups.
Conclusion: In a population of patients with ATTR amyloidosis, frailty remains a substantial problem among a large minority of patients. We strongly recommend its assessment in all ATTR-CA. This can be easily achieved, in less than 10 min, using the simple, easy- to learn and simple to perform, SPPB score.
Abstract
Topic: Imaging
Subtopic: Cardiac
Background: Transthyretin cardiac amyloidosis (ATTR-CA) results in a progressive, restrictive cardiomyopathy. Conventional staging utilises serum biomarkers (NT-proBNP, troponin and eGFR); however, limitations include variations in assays between centres. We investigated conventional biomarker and novel echocardiographic techniques in predicting mortality in ATTR-CA.
Method: Consecutive patients seen in a quaternary referral amyloidosis centre in Sydney, Australia, who underwent transthoracic echocardiogram were retrospectively recruited. All patients had ATTR-CA diagnosis confirmed by bone scintigraphy in the absence of a monoclonal gammopathy, or by endomyocardial biopsy. The outcome of all-cause mortality was monitored through patient medical records.
Results: 133 patients were consecutively enrolled. Over a median follow-up of 2.1 years, 31/133 (23%) died. Patients who died were older (81 ± 7 vs 75 ± 11 years, p <0.001), more likely to be male (97% vs 73%, p = .028), with more renal dysfunction (eGFR 56 ± 19 vs 67 ± 19, p = .007). Non-survivors had greater indexed LV mass (193 ± 52 g/m2 vs 155 ± 45 g/m2 , p < .001) and left atrial volume (61.4 ± 16 mL/m2 vs 53.6 ± 16 mL/m2, p = .023), as well as more pronounced reduction in systolic function including LVEF (52 ± 7% vs 55 ± 10%, p = .032) and LVGLS (10.8 ± 2.7% vs 12.8 ± 4.1%, p = .003). A composite echocardiographic risk score comprising LVGLS and indexed left atrial volume (LAVI) stratified patients into 3 distinct prognostic groups, akin to conventional staging systems.
Conclusion: Both conventional biomarkers and novel echocardiographic parameters are predictors of outcome in ATTR-CA. A novel echocardiographic prognostic score stratified patients into distinct risk groups, identifying a low-risk group with excellent long-term prognosis. Further evaluation by validation in another patient cohort is required.
Abstract
Topic: Prognosis ATTR
Background and hypothesis: ATTR amyloidosis is associated with low transthyretin (TTR, prealbumin) levels while stabilizer therapy is expected to increase it. We investigated the association between baseline and follow up TTR levels after initiation of tafamidis and mortality in ATTR cardiomyopathy.
Methods: We retrospectively evaluated ATTR cardiomyopathy patients who had prealbumin levels measured at baseline and 6 months after start of therapy. Patients were divided into two groups based on lower prealbumin at follow up than baseline and stable or higher prealbumin than baseline. The hazard ratio was calculated using outcomes cox regression model.
Results: A total of 90 patients were studied (age 77 ± 9 year, 16% women, 24% ATTRv). Median baseline prealbumin was 22 mg/dL and median follow up prealbumin was 26 mg/dL; 24 patients (26.6%) had a reduction in prealbumin compared to baseline. There was no significant difference in NT proBNP, serum creatinine and interventricular septal thickness on echocardiogram between the two groups. After adjustments of confounding variables, neither the baseline prealbumin level (HR 0.90, CI 0.83–0.98, p 0.2) nor a change in prealbumin at follow up had an association with mortality (HR 0.79, CI 0.17–3.7, p 0.76 for reduction and HR 1.25 CI 0.27–5.86 p 0.76 for stable or increased prealbumin).
Conclusion: There is no association between baseline TTR levels or its change after 6 months of tafamidis treatment in patients with ATTR cardiomyopathy
Abstract
Topic: Imaging
Subtopic: Radionuclides
Introduction: Left atrial (LA) structure and function are abnormal in light-chain (AL) amyloidosis. However, amyloid deposits in the LA have not been well characterized.
Objective: Use 18F-florbetapir PET/CT to (1) quantify LA amyloid (2) measure correlations between LA amyloid and metrics of LA structure/function and cardiac biomarkers, and (3) assess changes in LA amyloid post-plasma cell-directed therapy.
Methods: We studied 81 newly diagnosed AL amyloidosis subjects (median age 62 years, 55% males) with cardiomyopathy (n = 61, AL-CMP) or without cardiomyopathy (n = 20, AL-non-CMP) (based on serum cardiac biomarkers and left ventricular (LV) wall thickness), 25 subjects in AL amyloidosis remission (ALrem-CMP) and 8 controls. 18F-florbetapir PET/CT, cardiac MRI, and echocardiography were performed. LA uptake was measured as percent injected dose (measured activity concentration/injected activity x activity volume, %ID) on fused static PET/CT images (4–30 min) using a threshold of > mean +2SD of blood pool activity. Newly diagnosed patients underwent serial imaging 6 months post-treatment.
Results: LA %ID was significantly higher in AL-amyloidosis groups compared to controls (Figure 1A). In AL amyloidosis, LA %ID correlated significantly with LA strain (Figure 1B), as well as MRI LA volume (Figure 1C), and NT-proBNP (Figure 1D) (all p < .001). Six months post-treatment, there was a small decrease in LA %ID in the AL-CMP cohort (p = .03).
Conclusions: 18F-florbetapir PET/CT measured clinically relevant LA amyloid deposits; these deposits correlate with LA structure/function, and cardiac biomarker levels, and may improve following therapy. Imaging LA amyloid burden may have important implications for prediction of thromboembolic risk in patients with AL amyloidosis.
